I have a solution with a lot of project. Few of them are using EDMX. It looks like I did something that crashed my EDMX files. When I open EDMX and click option "Update Model from Database" I get a exception popup windows with message: "An unexpected exception has occurred. The exception message is: 'Exception has been thrown by the target of invocation.'."
And interesting is it doesn't matter which project. Any EDMX in the solution give me this bug. I have VS 2015 with latest EF 6.1.3.
Please help me :)
not sure if any one else is still having this issue. But I found a possible solution.
Open View > Server Explorer. then open the 'data connections' node and delete any connections in there.
This seemed to have fixed it for me.
I ran windbg.exe as well and found it was throwing an exception in Microsoft.AspNet.SignalR.WebSockets.WebSocketHandler
Hope this helps