After releasing ASP.NET and Web Tools 2012.2, which is also included in Visual Studio 2012 update 2, we've received a few customer feedback about their VS shows an error dialog saying: An exception has been encountered. This may be caused by an extension. You can get more information by examining the file 'C:\Users\<username>\AppData\Roaming\Microsoft\VisualStudio\12.0\ActivityLog.xml'. When looking at ActivityLog.xml, the following error message may show up: System.ComponentModel.Composition.ImportCardinalityMismatchException: Duplicate EditorFormatDefinition exports with identical name attributes exist. Duplicate name is LESSCSSVARIABLEDECLARATIONCLASSIFICATIONFORMAT To solve this problem, one just need to update the " Web Essentials...(read more)
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