VS2010 “An item with the same key has already been added”

Question

I recently installed Visual Studio 2010 and copied and converted an old VS2005 solution to VS2010

When I edit this solution, if I try to change a control\'s .image p

Answer 1

If you get this error during a SSDT Publish action, check you have not duplicated SqlCmdVariable entries in the Publish.xml file.

Answer 2

go inside properties/PublishProfiles, open the .pubxml file and check to see if your connection strings have been repeated. I had this issue, removed all the duplicate connection strings to leave one remaining and it solved my issue.