I've read through a couple of previous similar questions and none seem to provide a fix. So I ask again.
I'm using Visual Studio and am trying to connect to a DB in Server Explorer.
Regardless of what database I try to connect to it gives a "Given Key not Present in the Dictionary" error.
I have tried with SQL CE and SQL Express 2008 databases and each give the same issue.
I can connect quite easily with SQL Management Studio Express so I believe the Databases are the same.
after a lot of time searching for the answer to this i found the solution here
this is not really a workaround but in fact a SOLUTION, how to get rid of the error, in case you have missed to remove all connections before removing the provider:
edit C:\Users...\AppData\Roaming\Microsoft\VisualStudio\10.0\ServerExplorer\DefaultView.SEView and remove the connection with the wrong Provider manually. If you do not know which of the provider is failing, simply delete the file :)
If this won't help try deleting also C:\Users...\AppData\Local\Microsoft\VisualStudio\10.0
PS: you have to quit all instances of visual studios first or the files will be re-created from memory ..
The second part only worked for me , deleting the whole folder.