diff --git a/python/module/openstudio.py b/python/module/openstudio.py
index 62e8260b440..ee9c1bad671 100644
--- a/python/module/openstudio.py
+++ b/python/module/openstudio.py
@@ -50,7 +50,10 @@
         # When we're using system python to load the **installed** C:\openstudio-X.Y-Z\Python stuff (not PyPi package)
         # This allows finding openstudiolib.dll and the msvc ones in the bin/ folder while we're in the Python/ folder
         # Otherwise you'd have to manually copy these DLLs from bin/ to Python/
-        os.add_dll_directory(os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'bin')))
+        bin_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'bin'))
+        if os.path.isdir(bin_dir):
+            os.add_dll_directory(bin_dir)
+
     import openstudioairflow as airflow
     import openstudioenergyplus as energyplus
     import openstudioepjson as epjson
diff --git a/ruby/engine/embedded_help.rb b/ruby/engine/embedded_help.rb
index 95e205dd9db..6a9666a982c 100644
--- a/ruby/engine/embedded_help.rb
+++ b/ruby/engine/embedded_help.rb
@@ -3,6 +3,8 @@
 #  See also https://openstudio.net/license
 ########################################################################################################################
 
+require 'stringio'
+
 module EmbeddedScripting
   @@fileNames = EmbeddedScripting::allFileNamesAsString.split(';')
 
@@ -56,6 +58,17 @@ def self.preprocess_ruby_script(s)
 # DLM: ignore for now
 #Encoding.default_external = Encoding::ASCII
 
+# We patch Kernel.open, and IO.open
+# to read embedded files as a StringIO, not as a FileIO
+# But Gem.open_file for eg expects it to be a File, not a StringIO, and on
+# Windows it will call File::flock (file lock) to protect access, but StringIO
+# does not have this method
+class FakeFileAsStringIO < StringIO
+  def flock(operation)
+    return 0
+  end
+end
+
 module Kernel
   # ":" is our root path to the embedded file system
   # make sure it is in the ruby load path
@@ -329,7 +342,7 @@ def open(name, *args, **options)
         #puts "string = #{string}"
         if block_given?
           # if a block is given, then a new IO is created and closed
-          io = StringIO.open(string)
+          io = FakeFileAsStringIO.open(string)
           begin
             result = yield(io)
           ensure
@@ -337,13 +350,13 @@ def open(name, *args, **options)
           end
           return result
         else
-          return StringIO.open(string)
+          return FakeFileAsStringIO.open(string)
         end
       else
         #puts "IO.open cannot find embedded file '#{absolute_path}' for '#{name}'"
         if block_given?
           # if a block is given, then a new IO is created and closed
-          io = StringIO.open("")
+          io = FakeFileAsStringIO.open("")
           begin
             result = yield(io)
           ensure
@@ -459,7 +472,7 @@ def self.open(name, *args, **options)
         #puts "string = #{string}"
         if block_given?
           # if a block is given, then a new IO is created and closed
-          io = StringIO.open(string)
+          io = FakeFileAsStringIO.open(string)
           begin
             result = yield(io)
           ensure
@@ -467,13 +480,13 @@ def self.open(name, *args, **options)
           end
           return result
         else
-          return StringIO.open(string)
+          return FakeFileAsStringIO.open(string)
         end
       else
         puts "IO.open cannot find embedded file '#{absolute_path}' for '#{name}'"
         if block_given?
           # if a block is given, then a new IO is created and closed
-          io = StringIO.open("")
+          io = FakeFileAsStringIO.open("")
           begin
             result = yield(io)
           ensure
diff --git a/src/cli/CMakeLists.txt b/src/cli/CMakeLists.txt
index e79684fcdfc..74c557322a6 100644
--- a/src/cli/CMakeLists.txt
+++ b/src/cli/CMakeLists.txt
@@ -203,6 +203,11 @@ if(BUILD_TESTING)
     PASS_REGULAR_EXPRESSION "Hello from -x, at National Renewable Energy Laboratory"
   )
 
+  # Test for 5315
+  add_test(NAME OpenStudioCLI.EmbeddedScripting.uuid
+    COMMAND $<TARGET_FILE:openstudio> ${CMAKE_CURRENT_SOURCE_DIR}/test/ensure_uuid_can_be_loaded.rb
+  )
+
   add_test(NAME OpenStudioCLI.Classic.Run_RubyOnly
     COMMAND $<TARGET_FILE:openstudio> classic run -w compact_ruby_only.osw
     WORKING_DIRECTORY "${PROJECT_BINARY_DIR}/resources/Examples/compact_osw/"
diff --git a/src/cli/test/ensure_uuid_can_be_loaded.rb b/src/cli/test/ensure_uuid_can_be_loaded.rb
new file mode 100644
index 00000000000..41e4cfd19b5
--- /dev/null
+++ b/src/cli/test/ensure_uuid_can_be_loaded.rb
@@ -0,0 +1,5 @@
+require 'uuid'
+
+u = UUID.new
+
+puts u.inspect