We are using Work Flow's in our project and it is developed in VS 2010. Recently we migrated to VS 2013 Professional. Now when we try to open a Work Flow Activity in VS 2013, we get the following error message:
System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.VisualStudio.SharePoint.WorkflowExtensions, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified. File name: 'Microsoft.VisualStudio.SharePoint.WorkflowExtensions, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'"
We could find the "Microsoft.VisualStudio.SharePoint.WorkflowExtensions.dll" under "C:\Program Files\Microsoft Visual Studio 12.0\Common7\IDE\Extensions\WorkflowDesigner", but still when we open the WF designer, we get the FileNotFound exception.
When we close and open the WF again, we get the below error message :
System.ArgumentException: An item with the same key has already been added.
at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
at Microsoft.VisualStudio.Activities.EditorPane.set_FileName(String value)
at Microsoft.VisualStudio.Activities.EditorPane.Microsoft.VisualStudio.Shell.Interop.IPersistFileFormat.Load(String fileName, UInt32 formatMode, Int32 readOnly)
Any idea what is causing the issue ?