Error while saving EDMX file

while saving NorthwindIB.edmx file this erro pops up ...

please help to solve the problem

Error    1    An exception was thrown while trying to compile the transformation code. The following Exception was thrown:
System.BadImageFormatException: Could not load file or assembly 'file:///C:\Users\Sakar\AppData\Local\Temp\3mxmxqxu.dll' or one of its dependencies. The module was expected to contain an assembly manifest.
File name: 'file:///C:\Users\Sakar\AppData\Local\Temp\3mxmxqxu.dll'
   at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.Assembly.Load(AssemblyName assemblyRef, Evidence assemblySecurity)
   at System.CodeDom.Compiler.CompilerResults.get_CompiledAssembly()
   at Microsoft.VisualStudio.TextTemplating.TransformationRunner.Compile(String source, String inputFile, IEnumerable`1 references, Boolean debug, CodeDomProvider provider, String compilerOptions)

WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
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