I just installed SlickEdit 2011 (16.0.0.6) and when starting it gives me the following error and the attached vsstack.
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Slick-C Error
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Invalid argument
file=MenuCustomizationHandler.ex offset=2983
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OK
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I had no problems like this with any of the VS 16 betas or with rc1. The error repeats every time I restart VS until I renamed the userMenus.xml. Initially I was using the 16.0.0 config directory that was originally created by beta 1. I renamed that and restarted VS and it copied my 15.0.1 config directory and then gave me the same error.