http://blogs.msdn.com/b/vsnetsetup/archive/2010/08/21/help-library-agent-exception-system-collections-generic-keynotfoundexception-the-given-key-was-not-present-in-the-dictionary.aspxOn a windows 7 operating system, you may run into this error when HelpLibAgent.exe crashes while accessing help feature in Visual studio 2010. To fix this problem, please follow the link below   http://blogs.msdn.com/b/smondal/archive/2010/06/22en-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)