Visual Studio has encountered an exception. This may be caused by an extension.

We've seen this issue before and have a workaround you can use to get VS working again. It's due to missing registry information. To confirm this is the issue you are seeing, can you examine the following registry key:

On 32-Bit Windows: [HKEY_CLASSES_ROOT\CLSID\{73B7DC00-F498-4ABD-AB79-D07AFD52F395}\InProcServer32]
On 64-Bit Windows: [HKEY_CLASSES_ROOT\Wow6432Node\CLSID\{73B7DC00-F498-4ABD-AB79-D07AFD52F395}\InProcServer32]

The "(Default)" value should be one of the following:
On 32-Bit Windows: "C:\Program Files\Common Files\Microsoft Shared\MSEnv\TextMgrP.dll"
On 64-Bit Windows: "C:\Program Files (x86)\Common Files\Microsoft Shared\MSEnv\TextMgrP.dll"

If your registry is different, then you can do one of the following:
1. Reinstall Visual Studio 2010 RTM. This should resolve the issue.
2. Modify the registry with the value mentioned above(This Approach Works! Tried Myself!). NOTE: Modifying the registry can be dangerous. Please backup your registry information before making changes.

 

Original Links:

https://connect.microsoft.com/VisualStudio/feedback/details/612951/vs2010-editor-exception-on-c-files?wa=wsignin1.0#tabs