diff --git a/core/shared/src/main/scala/sigma/SigmaDsl.scala b/core/shared/src/main/scala/sigma/SigmaDsl.scala
index 422e4b796..16331febf 100644
--- a/core/shared/src/main/scala/sigma/SigmaDsl.scala
+++ b/core/shared/src/main/scala/sigma/SigmaDsl.scala
@@ -592,13 +592,13 @@ trait Context {
   /**
     * A variant of `getVar` to extract a context variable by id and type from any input
     *
-    * @param inputId - input index
+    * @param inputIndex - input index
     * @param id - context variable id
     * @tparam T - expected type of the variable
     * @return Some(value) if the variable is defined in the context AND has the given type.
     *         None otherwise
     */
-  def getVarFromInput[T](inputId: Short, id: Byte)(implicit cT: RType[T]): Option[T]
+  def getVarFromInput[T](inputIndex: Short, id: Byte)(implicit cT: RType[T]): Option[T]
 
   def vars: Coll[AnyValue]
 
diff --git a/interpreter/shared/src/main/scala/sigmastate/eval/CContext.scala b/interpreter/shared/src/main/scala/sigmastate/eval/CContext.scala
index bed0c4b01..b0e5b0118 100644
--- a/interpreter/shared/src/main/scala/sigmastate/eval/CContext.scala
+++ b/interpreter/shared/src/main/scala/sigmastate/eval/CContext.scala
@@ -73,8 +73,8 @@ case class CContext(
     } else None
   }
 
-  override def getVarFromInput[T](inputId: Short, id: Byte)(implicit tT: RType[T]): Option[T] = {
-    spendingTransaction.inputs.lift(inputId).flatMap(_.extension.get(id)) match {
+  override def getVarFromInput[T](inputIndex: Short, id: Byte)(implicit tT: RType[T]): Option[T] = {
+    spendingTransaction.inputs.lift(inputIndex).flatMap(_.extension.get(id)) match {
       case Some(v) if stypeToRType[SType](v.tpe) == tT => Some(v.value.asInstanceOf[T])
       case _ =>
         None
diff --git a/sc/shared/src/test/scala/sigmastate/lang/SigmaTyperTest.scala b/sc/shared/src/test/scala/sigmastate/lang/SigmaTyperTest.scala
index 5bfb72cd4..c86cb11af 100644
--- a/sc/shared/src/test/scala/sigmastate/lang/SigmaTyperTest.scala
+++ b/sc/shared/src/test/scala/sigmastate/lang/SigmaTyperTest.scala
@@ -687,6 +687,12 @@ class SigmaTyperTest extends AnyPropSpec
     typecheck(env, "CONTEXT.getVar[Int](1.toByte).get") shouldBe SInt
   }
 
+  property("SContext.getVarFromInput") {
+    runWithVersion(VersionContext.V6SoftForkVersion) {
+      typecheck(env, "CONTEXT.getVarFromInput[Int](1.toShort, 1.toByte).get") shouldBe SInt
+    }
+  }
+
   property("SAvlTree.digest") {
     typecheck(env, "getVar[AvlTree](1).get.digest") shouldBe SByteArray
   }
diff --git a/sc/shared/src/test/scala/sigmastate/utxo/BasicOpsSpecification.scala b/sc/shared/src/test/scala/sigmastate/utxo/BasicOpsSpecification.scala
index ea9539a65..0eba3c987 100644
--- a/sc/shared/src/test/scala/sigmastate/utxo/BasicOpsSpecification.scala
+++ b/sc/shared/src/test/scala/sigmastate/utxo/BasicOpsSpecification.scala
@@ -7,7 +7,7 @@ import scorex.util.encode.Base16
 import scorex.utils.Ints
 import sigma.Extensions.ArrayOps
 import sigma.{SigmaTestingData, VersionContext}
-import sigma.VersionContext.V6SoftForkVersion
+import sigma.VersionContext.{V6SoftForkVersion, withVersions}
 import sigma.ast.SCollection.SByteArray
 import sigma.ast.SType.AnyOps
 import sigma.data.{AvlTreeData, CAnyValue, CSigmaDslBuilder}
@@ -19,7 +19,7 @@ import sigmastate._
 import sigmastate.helpers.TestingHelpers._
 import sigmastate.helpers.{CompilerTestingCommons, ContextEnrichingTestProvingInterpreter, ErgoLikeContextTesting, ErgoLikeTestInterpreter}
 import sigma.interpreter.ContextExtension.VarBinding
-import sigmastate.interpreter.CErgoTreeEvaluator.DefaultEvalSettings
+import sigmastate.interpreter.CErgoTreeEvaluator.{DefaultEvalSettings, currentEvaluator}
 import sigmastate.interpreter.Interpreter._
 import sigma.ast.Apply
 import sigma.eval.EvalSettings
@@ -92,8 +92,11 @@ class BasicOpsSpecification extends CompilerTestingCommons
       // is not supported by ErgoScript Compiler)
       // In such cases we use expected property as the property to test
       propExp.asSigmaProp
-    } else
-      compile(env, script).asBoolValue.toSigmaProp
+    } else {
+      withVersions(VersionContext.MaxSupportedScriptVersion, ergoTreeVersionInTests) {
+        compile(env, script).asBoolValue.toSigmaProp
+      }
+    }
 
     if (propExp != null)
       prop shouldBe propExp
@@ -145,20 +148,6 @@ class BasicOpsSpecification extends CompilerTestingCommons
     flexVerifier.verify(verifyEnv, tree, ctxExt, pr.proof, fakeMessage).get._1 shouldBe true
   }
 
-  property("Context.getVar") {
-    def varTest() = {
-      test("GetVar1", env, ext,
-        "{ CONTEXT.getVar[Int](intVar2.toByte).get == 2 }",
-        null
-      )
-    }
-
-    if(VersionContext.current.isV6SoftForkActivated) {
-      varTest()
-    } else {
-      an[Exception] should be thrownBy(varTest())
-    }
-  }
 
   property("getVarFromInput") {
     def getVarTest(): Assertion = {
@@ -174,7 +163,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       getVarTest()
     } else {
-      an[Exception] should be thrownBy getVarTest()
+      an[sigma.validation.ValidationException] should be thrownBy getVarTest()
     }
   }
 
@@ -195,7 +184,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       getVarTest()
     } else {
-      an[Exception] should be thrownBy getVarTest()
+      an[sigma.validation.ValidationException] should be thrownBy getVarTest()
     }
   }
 
@@ -213,13 +202,17 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       getVarTest()
     } else {
-      an[Exception] should be thrownBy getVarTest()
+      an[sigma.validation.ValidationException] should be thrownBy getVarTest()
     }
   }
+
   property("Byte.toBits") {
-    def toBitsTest() = test("Byte.toBits", env, ext,
+    val customExt = Map(
+      1.toByte -> ByteConstant(1)
+    ).toSeq
+    def toBitsTest() = test("Byte.toBits", env, customExt,
       """{
-        | val b = 1.toByte
+        | val b = getVar[Byte](1).get
         | b.toBits == Coll(false, false, false, false, false, false, false, true)
         |}""".stripMargin,
       null
@@ -228,14 +221,17 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       toBitsTest()
     } else {
-      an[Exception] shouldBe thrownBy(toBitsTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(toBitsTest())
     }
   }
 
   property("Long.toBits") {
-    def toBitsTest() = test("Long.toBits", env, ext,
+    val customExt = Map(
+      1.toByte -> LongConstant(1)
+    ).toSeq
+    def toBitsTest() = test("Long.toBits", env, customExt,
       """{
-        | val b = 1L
+        | val b = getVar[Long](1).get
         | val ba = b.toBits
         |
         | // only rightmost bit is set
@@ -247,7 +243,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       toBitsTest()
     } else {
-      an[Exception] shouldBe thrownBy(toBitsTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(toBitsTest())
     }
   }
 
@@ -264,7 +260,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       toBitsTest()
     } else {
-      an[Exception] shouldBe thrownBy(toBitsTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(toBitsTest())
     }
   }
 
@@ -281,10 +277,11 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       bitwiseInverseTest()
     } else {
-      an[Exception] shouldBe thrownBy(bitwiseInverseTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(bitwiseInverseTest())
     }
   }
 
+
   property("Byte.bitwiseInverse") {
     def bitwiseInverseTest(): Assertion = test("Byte.bitwiseInverse", env, ext,
       s"""{
@@ -297,14 +294,17 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       bitwiseInverseTest()
     } else {
-      an[Exception] shouldBe thrownBy(bitwiseInverseTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(bitwiseInverseTest())
     }
   }
 
   property("Long.bitwiseInverse") {
-    def bitwiseInverseTest(): Assertion = test("Long.bitwiseInverse", env, ext,
+    val customExt = Map(
+      1.toByte -> LongConstant(9223372036854775807L)
+    ).toSeq
+    def bitwiseInverseTest(): Assertion = test("Long.bitwiseInverse", env, customExt,
       s"""{
-         | val l = 9223372036854775807L
+         | val l = getVar[Long](1).get
          | val lb = l.bitwiseInverse
          | lb.bitwiseInverse == l
          |}""".stripMargin,
@@ -314,14 +314,18 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       bitwiseInverseTest()
     } else {
-      an[Exception] shouldBe thrownBy(bitwiseInverseTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(bitwiseInverseTest())
     }
   }
 
+
   property("Byte.bitwiseOr") {
-    def bitwiseOrTest(): Assertion = test("Byte.bitwiseOrTest", env, ext,
+    val customExt = Map(
+      1.toByte -> ByteConstant(127)
+    ).toSeq
+    def bitwiseOrTest(): Assertion = test("Byte.bitwiseOrTest", env, customExt,
       s"""{
-         | val x = 127.toByte
+         | val x = getVar[Byte](1).get
          | val y = (-128).toByte
          | x.bitwiseOr(y) == -1
          |}""".stripMargin,
@@ -331,7 +335,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       bitwiseOrTest()
     } else {
-      an[Exception] shouldBe thrownBy(bitwiseOrTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(bitwiseOrTest())
     }
   }
 
@@ -347,7 +351,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       bitwiseOrTest()
     } else {
-      an[Exception] shouldBe thrownBy(bitwiseOrTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(bitwiseOrTest())
     }
   }
 
@@ -364,14 +368,17 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       bitwiseAndTest()
     } else {
-      an[Exception] shouldBe thrownBy(bitwiseAndTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(bitwiseAndTest())
     }
   }
 
   property("Short.bitwiseAnd") {
-    def bitwiseAndTest(): Assertion = test("Short.bitwiseAnd", env, ext,
+    val customExt = Map(
+      1.toByte -> ShortConstant(32767)
+    ).toSeq
+    def bitwiseAndTest(): Assertion = test("Short.bitwiseAnd", env, customExt,
       s"""{
-         | val x = (32767).toShort
+         | val x = getVar[Short](1).get
          | val y = (-32768).toShort
          | x.bitwiseAnd(y) == 0
          |}""".stripMargin,
@@ -381,14 +388,17 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       bitwiseAndTest()
     } else {
-      an[Exception] shouldBe thrownBy(bitwiseAndTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(bitwiseAndTest())
     }
   }
 
   property("Short.bitwiseXor") {
-    def bitwiseXorTest(): Assertion = test("Short.bitwiseXor", env, ext,
+    val customExt = Map(
+      1.toByte -> ShortConstant(32767)
+    ).toSeq
+    def bitwiseXorTest(): Assertion = test("Short.bitwiseXor", env, customExt,
       s"""{
-         | val x = (32767).toShort
+         | val x = getVar[Short](1).get
          | val y = (-32768).toShort
          | x.bitwiseXor(y) == -1
          |}""".stripMargin,
@@ -398,7 +408,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       bitwiseXorTest()
     } else {
-      an[Exception] shouldBe thrownBy(bitwiseXorTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(bitwiseXorTest())
     }
   }
 
@@ -415,7 +425,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       shiftLeftTest()
     } else {
-      an[Exception] shouldBe thrownBy(shiftLeftTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftLeftTest())
     }
   }
 
@@ -432,7 +442,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       an[IllegalArgumentException] shouldBe thrownBy(shiftLeftTest())
     } else {
-      an[Exception] shouldBe thrownBy(shiftLeftTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftLeftTest())
     }
   }
 
@@ -449,7 +459,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       shiftLeftTest()
     } else {
-      an[Exception] shouldBe thrownBy(shiftLeftTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftLeftTest())
     }
   }
 
@@ -466,7 +476,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       shiftLeftTest()
     } else {
-      an[Exception] shouldBe thrownBy(shiftLeftTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftLeftTest())
     }
   }
 
@@ -482,7 +492,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       an[ArithmeticException] shouldBe thrownBy(shiftLeftTest())
     } else {
-      an[Exception] shouldBe thrownBy(shiftLeftTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftLeftTest())
     }
   }
 
@@ -499,7 +509,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       shiftRightTest()
     } else {
-      an[Exception] shouldBe thrownBy(shiftRightTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftRightTest())
     }
   }
 
@@ -516,7 +526,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       shiftRightTest()
     } else {
-      an[Exception] shouldBe thrownBy(shiftRightTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftRightTest())
     }
   }
 
@@ -533,10 +543,11 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       an[IllegalArgumentException] shouldBe thrownBy(shiftRightTest())
     } else {
-      an[Exception] shouldBe thrownBy(shiftRightTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftRightTest())
     }
   }
 
+
   property("Long.shiftRight - neg") {
     def shiftRightTest(): Assertion = test("Long.shiftRight", env, ext,
       s"""{
@@ -550,7 +561,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       shiftRightTest()
     } else {
-      an[Exception] shouldBe thrownBy(shiftRightTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftRightTest())
     }
   }
 
@@ -567,7 +578,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       an[IllegalArgumentException] shouldBe thrownBy(shiftRightTest())
     } else {
-      an[Exception] shouldBe thrownBy(shiftRightTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftRightTest())
     }
   }
 
@@ -585,7 +596,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       shiftRightTest()
     } else {
-      an[Exception] shouldBe thrownBy(shiftRightTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftRightTest())
     }
   }
 
@@ -603,7 +614,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       an[IllegalArgumentException] shouldBe thrownBy(shiftRightTest())
     } else {
-      an[Exception] shouldBe thrownBy(shiftRightTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(shiftRightTest())
     }
   }
 
@@ -621,7 +632,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       getVarTest()
     } else {
-      an[Exception] should be thrownBy getVarTest()
+      an[sigma.validation.ValidationException] should be thrownBy getVarTest()
     }
   }
 
@@ -642,7 +653,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       reverseTest()
     } else {
-      an[Exception] shouldBe thrownBy(reverseTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(reverseTest())
     }
   }
 
@@ -663,7 +674,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       reverseTest()
     } else {
-      an[Exception] shouldBe thrownBy(reverseTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(reverseTest())
     }
   }
 
@@ -687,7 +698,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       reverseTest()
     } else {
-      an[Exception] shouldBe thrownBy(reverseTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(reverseTest())
     }
   }
 
@@ -711,7 +722,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       reverseTest()
     } else {
-      an[Exception] shouldBe thrownBy(reverseTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(reverseTest())
     }
   }
 
@@ -735,7 +746,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       reverseTest()
     } else {
-      an[Exception] shouldBe thrownBy(reverseTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(reverseTest())
     }
   }
 
@@ -759,7 +770,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       reverseTest()
     } else {
-      an[Exception] shouldBe thrownBy(reverseTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(reverseTest())
     }
   }
 
@@ -777,7 +788,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       getTest()
     } else {
-      an[Exception] shouldBe thrownBy(getTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(getTest())
     }
   }
 
@@ -793,7 +804,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       fromTest()
     } else {
-      an[Exception] should be thrownBy(fromTest())
+      an[sigma.validation.ValidationException] should be thrownBy(fromTest())
     }
   }
 
@@ -809,7 +820,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       fromTest()
     } else {
-      an[Exception] should be thrownBy(fromTest())
+      an[sigma.validation.ValidationException] should be thrownBy(fromTest())
     }
   }
 
@@ -825,7 +836,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       fromTest()
     } else {
-      an[Exception] should be thrownBy(fromTest())
+      an[sigma.validation.ValidationException] should be thrownBy(fromTest())
     }
   }
 
@@ -842,14 +853,17 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       fromTest()
     } else {
-      an[Exception] should be thrownBy(fromTest())
+      an[sigma.validation.ValidationException] should be thrownBy(fromTest())
     }
   }
 
   property("Global.fromBigEndianBytes - Long.toBytes") {
-    def fromTest() = test("fromBigEndianBytes - long", env, ext,
+    val customExt = Map(
+      1.toByte -> LongConstant(1088800L)
+    ).toSeq
+    def fromTest() = test("fromBigEndianBytes - long", env, customExt,
       s"""{
-         |  val l = 1088800L
+         |  val l = getVar[Long](1).get
          |  val ba = l.toBytes
          |  Global.fromBigEndianBytes[Long](ba) == l
          |}
@@ -859,7 +873,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       fromTest()
     } else {
-      an[Exception] should be thrownBy(fromTest())
+      an[sigma.validation.ValidationException] should be thrownBy(fromTest())
     }
   }
 
@@ -876,14 +890,17 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       fromTest()
     } else {
-      an[Exception] should be thrownBy(fromTest())
+      an[sigma.validation.ValidationException] should be thrownBy(fromTest())
     }
   }
 
   property("Int.toBytes") {
-    def toBytesTest() = test("Int.toBytes", env, ext,
+    val customExt = Map(
+      1.toByte -> IntConstant(1)
+    ).toSeq
+    def toBytesTest() = test("Int.toBytes", env, customExt,
       """{
-        |   val l = 1
+        |   val l = getVar[Int](1).get
         |   l.toBytes == Coll(0.toByte, 0.toByte, 0.toByte, 1.toByte)
         | }""".stripMargin,
       null
@@ -892,14 +909,17 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       toBytesTest()
     } else {
-      an[Exception] shouldBe thrownBy(toBytesTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(toBytesTest())
     }
   }
 
   property("Int.toBits") {
-    def toBytesTest() = test("Int.toBytes", env, ext,
+    val customExt = Map(
+      1.toByte -> IntConstant(1477959696)
+    ).toSeq
+    def toBytesTest() = test("Int.toBytes", env, customExt,
       """{
-        |   val l = 1477959696
+        |   val l = getVar[Int](1).get
         |   l.toBits == Coll(false, true, false, true, true, false, false, false, false, false, false, true, false, true, true ,true, true, true, true, false, false, false, false, false, false, false, false, true, false, false, false, false)
         | }""".stripMargin,
       null
@@ -908,14 +928,17 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       toBytesTest()
     } else {
-      an[Exception] shouldBe thrownBy(toBytesTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(toBytesTest())
     }
   }
 
   property("Byte.toBytes") {
-    def toBytesTest() = test("Byte.toBytes", env, ext,
+    val customExt = Map(
+      1.toByte -> ByteConstant(10)
+    ).toSeq
+    def toBytesTest() = test("Byte.toBytes", env, customExt,
       """{
-        |   val l = 10.toByte
+        |   val l = getVar[Byte](1).get
         |   l.toBytes == Coll(10.toByte)
         | }""".stripMargin,
       null
@@ -924,7 +947,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       toBytesTest()
     } else {
-      an[Exception] shouldBe thrownBy(toBytesTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(toBytesTest())
     }
   }
 
@@ -941,7 +964,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       toBytesTest()
     } else {
-      an[Exception] shouldBe thrownBy(toBytesTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(toBytesTest())
     }
   }
 
@@ -956,7 +979,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
 
     if (activatedVersionInTests < V6SoftForkVersion) {
-      an [sigma.exceptions.TyperException] should be thrownBy deserTest()
+      an [sigma.validation.ValidationException] should be thrownBy deserTest()
     } else {
       deserTest()
     }
@@ -973,7 +996,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
 
     if (activatedVersionInTests < V6SoftForkVersion) {
-      an [sigma.exceptions.TyperException] should be thrownBy deserTest()
+      an [sigma.validation.ValidationException] should be thrownBy deserTest()
     } else {
       deserTest()
     }
@@ -990,7 +1013,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
 
     if (activatedVersionInTests < V6SoftForkVersion) {
-      an [sigma.exceptions.TyperException] should be thrownBy deserTest()
+      an [sigma.validation.ValidationException] should be thrownBy deserTest()
     } else {
       deserTest()
     }
@@ -1009,7 +1032,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
 
     if (activatedVersionInTests < V6SoftForkVersion) {
-      an [sigma.exceptions.TyperException] should be thrownBy deserTest()
+      an [sigma.validation.ValidationException] should be thrownBy deserTest()
     } else {
       deserTest()
     }
@@ -1030,7 +1053,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
 
     if (activatedVersionInTests < V6SoftForkVersion) {
-      an [Exception] should be thrownBy deserTest()
+      an [sigma.validation.ValidationException] should be thrownBy deserTest()
     } else {
       deserTest()
     }
@@ -1051,7 +1074,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
 
     if (activatedVersionInTests < V6SoftForkVersion) {
-      an [Exception] should be thrownBy deserTest()
+      an [sigma.validation.ValidationException] should be thrownBy deserTest()
     } else {
       deserTest()
     }
@@ -1075,7 +1098,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
 
     if (activatedVersionInTests < V6SoftForkVersion) {
-      an [sigma.exceptions.TyperException] should be thrownBy deserTest()
+      an [sigma.validation.ValidationException] should be thrownBy deserTest()
     } else {
       deserTest()
     }
@@ -1100,7 +1123,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
 
     if (activatedVersionInTests < V6SoftForkVersion) {
-      an[Exception] should be thrownBy deserTest()
+      an[sigma.validation.ValidationException] should be thrownBy deserTest()
     } else {
       deserTest()
     }
@@ -1122,7 +1145,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
 
     if (activatedVersionInTests < V6SoftForkVersion) {
-      an[Exception] should be thrownBy deserTest()
+      an[sigma.validation.ValidationException] should be thrownBy deserTest()
     } else {
       // we have wrapped CostLimitException here
       an[Exception] should be thrownBy deserTest()
@@ -1162,7 +1185,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       optTest()
     } else {
-      an[Exception] shouldBe thrownBy(optTest())
+      assertExceptionThrown(optTest(), _.isInstanceOf[NoSuchElementException])
     }
   }
 
@@ -1485,7 +1508,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if(VersionContext.current.isV6SoftForkActivated) {
       holTest()
     } else {
-      an[Exception] shouldBe thrownBy(holTest())
+      an[sigma.validation.ValidationException] shouldBe thrownBy(holTest())
     }
   }
 
@@ -1799,11 +1822,15 @@ class BasicOpsSpecification extends CompilerTestingCommons
   }
 
   property("Box.getReg") {
+    val customExt = Map(
+      1.toByte -> IntConstant(0)
+    ).toSeq
     def getRegTest(): Assertion = {
-      test("Box.getReg", env, ext,
+      test("Box.getReg", env, customExt,
         """{
+          |   val idx = getVar[Int](1).get
           |   val x = SELF
-          |   x.getReg[Long](0).get == SELF.value &&
+          |   x.getReg[Long](idx).get == SELF.value &&
           |   x.getReg[Coll[(Coll[Byte], Long)]](2).get == SELF.tokens &&
           |   x.getReg[Int](9).isEmpty
           |}""".stripMargin,
@@ -1814,7 +1841,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       getRegTest()
     } else {
-      an[Exception] should be thrownBy getRegTest()
+      an[sigma.exceptions.ConstraintFailed] should be thrownBy getRegTest()
     }
   }
 
@@ -1835,7 +1862,7 @@ class BasicOpsSpecification extends CompilerTestingCommons
     if (VersionContext.current.isV6SoftForkActivated) {
       getRegTest()
     } else {
-      an[Exception] should be thrownBy getRegTest()
+      an[java.nio.BufferUnderflowException] should be thrownBy getRegTest()
     }
   }