[SOLVED] The service '/app/notificationsregistrationhandler.svc' cannot be activated due to an exception during compilation

On developement site this REST web service works fine but on production site I get this error:

Server Error in '/app' Application.

The specified module could not be found. (Exception from HRESULT: 0x8007007E)

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.IO.FileNotFoundException: The specified module could not be found. (Exception from HRESULT: 0x8007007E)

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 


[FileNotFoundException: The specified module could not be found. (Exception from HRESULT: 0x8007007E)]
   System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) +0
   System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) +43
   System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +127
   System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +142
   System.Reflection.Assembly.Load(String assemblyString) +28
   System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +46

[ConfigurationErrorsException: The specified module could not be found. (Exception from HRESULT: 0x8007007E)]
   System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +613
   System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +203
   System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +105
   >System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +178
   System.Web.Compilation.WebDirectoryBatchCompiler..ctor(VirtualDirectory vdir) +163
   System.Web.Compilation.BuildManager.BatchCompileWebDirectoryInternal(VirtualDirectory vdir, Boolean ignoreErrors) +53
   System.Web.Compilation.BuildManager.BatchCompileWebDirectory(VirtualDirectory vdir, VirtualPath virtualDir, Boolean ignoreErrors) +175
   System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath) +86
System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile) +261
   System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile) +101
System.Web.Compilation.BuildManager.GetVPathBuildResult(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile) +83
System.Web.Compilation.BuildManager.GetCompiledCustomString(String virtualPath) +27
System.ServiceModel.HostingManager.GetCompiledCustomString(String normalizedVirtualPath) +134
System.ServiceModel.HostingManager.CreateService(String normalizedVirtualPath) +25
System.ServiceModel.HostingManager.ActivateService(String normalizedVirtualPath) +42
System.ServiceModel.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath) +479

[ServiceActivationException: The service '/app/notificationsregistrationhandler.svc' cannot be activated due to an exception during compilation.  The exception message is: The specified module could not be found. (Exception from HRESULT: 0x8007007E).]
   System.ServiceModel.AsyncResult.End(IAsyncResult result) +11653822
   System.ServiceModel.Activation.HostedHttpRequestAsyncResult.End(IAsyncResult result) +194
   System.ServiceModel.Activation.HostedHttpRequestAsyncResult.ExecuteSynchronous(HttpApplication context, Boolean flowContext) +176
   System.ServiceModel.Activation.HttpHandler.ProcessRequest(HttpContext context) +23
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +181
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

web.config on development site is the same on production site (except for datasource connection info).
KB is developed using Genexus EV3 U3 and was migrated from EV2 U7
Development site is Windows 7 sp3 and production site is Windows Server 2008 R2
Production site works fine except for REST web services
URL Rewrite module is configured
anotificationsregistrationhandler.dll is on bin directory

What else can I check?