diff --git a/DialogX/src/main/java/com/kongzue/dialogx/dialogs/BottomDialog.java b/DialogX/src/main/java/com/kongzue/dialogx/dialogs/BottomDialog.java
index c8d2663b..832dd902 100644
--- a/DialogX/src/main/java/com/kongzue/dialogx/dialogs/BottomDialog.java
+++ b/DialogX/src/main/java/com/kongzue/dialogx/dialogs/BottomDialog.java
@@ -519,7 +519,7 @@ public void refreshView() {
             boxRoot.setRootPadding(screenPaddings[0], screenPaddings[1], screenPaddings[2], screenPaddings[3]);
             if (backgroundColor != null) {
                 tintColor(bkg, backgroundColor);
-                if (style.tintButtonBackground()){
+                if (style.tintButtonBackground()) {
                     tintColor(btnSelectOther, backgroundColor);
                     tintColor(btnSelectNegative, backgroundColor);
                     tintColor(btnSelectPositive, backgroundColor);
@@ -542,7 +542,10 @@ public void refreshView() {
             useTextInfo(btnSelectPositive, okTextInfo);
 
             if (boxButton != null) {
-                boxButton.setVisibility(btnSelectNegative.getVisibility() == View.VISIBLE || btnSelectOther.getVisibility() == View.VISIBLE || btnSelectPositive.getVisibility() == View.VISIBLE ? View.VISIBLE : View.GONE);
+                boxButton.setVisibility((btnSelectNegative != null && btnSelectNegative.getVisibility() == View.VISIBLE) ||
+                        (btnSelectOther != null && btnSelectOther.getVisibility() == View.VISIBLE) ||
+                        (btnSelectPositive != null && btnSelectPositive.getVisibility() == View.VISIBLE) ?
+                        View.VISIBLE : View.GONE);
             }
             if (titleIcon != null) {
                 int size = (int) txtDialogTitle.getTextSize();
diff --git a/DialogX/src/main/java/com/kongzue/dialogx/dialogs/MessageDialog.java b/DialogX/src/main/java/com/kongzue/dialogx/dialogs/MessageDialog.java
index f76da9d5..05eebae8 100644
--- a/DialogX/src/main/java/com/kongzue/dialogx/dialogs/MessageDialog.java
+++ b/DialogX/src/main/java/com/kongzue/dialogx/dialogs/MessageDialog.java
@@ -663,7 +663,10 @@ public void getOutline(View view, Outline outline) {
             useTextInfo(btnSelectOther, otherTextInfo);
 
             if (boxButton != null) {
-                boxButton.setVisibility(btnSelectNegative.getVisibility() == View.VISIBLE || btnSelectOther.getVisibility() == View.VISIBLE || btnSelectPositive.getVisibility() == View.VISIBLE ? View.VISIBLE : View.GONE);
+                boxButton.setVisibility((btnSelectNegative != null && btnSelectNegative.getVisibility() == View.VISIBLE) ||
+                        (btnSelectOther != null && btnSelectOther.getVisibility() == View.VISIBLE) ||
+                        (btnSelectPositive != null && btnSelectPositive.getVisibility() == View.VISIBLE) ?
+                        View.VISIBLE : View.GONE);
             }
             if (titleIcon != null) {
                 int size = (int) txtDialogTitle.getTextSize();
diff --git a/gradle.properties b/gradle.properties
index 1a74cb14..d00d496f 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -19,7 +19,7 @@ android.useAndroidX=true
 # Automatically convert third-party libraries to use AndroidX
 android.enableJetifier=true
 
-BUILD_VERSION=0.0.50.beta18
+BUILD_VERSION=0.0.50.beta19
 BUILD_VERSION_INT=49
 DIALOGX_STYLE_VERSION=5
 android.nonTransitiveRClass=true