I had some issues with Test studio projects opening in VS.  I reported this issue to Telerik Support on Ticket ID 755261.  The main thing from the ticket to note is that the project would backup would throw this error:

[11/07 00:23:37,devenv.exe(6016:1),ProjectModel] Project.BackupProject() : EXCEPTION! (see below)
     Situation: Error creating project backup
     Outer Exception Type: System.IO.PathTooLongException
     Message: The specified path, file name, or both are too long. The fully qualified file name must be less than 260 characters, and the directory name must be less than 248 characters.
     HRESULT: 0x800700CE (Official ID (if app.) = 2147942606, Error Bit = FAILED, Facility = FACILITY_WIN32, Code = ERROR_FILENAME_EXCED_RANGE) 

With this in mind, I moved all automation projects' folder as close to my base C drive that I could instead of having it on my desktop with filepath of C:\users\name of user\folder... 

Even after moving my folders, I still had to shorten my automation folders to be a single folder deep and have my tests have shortened file name that I codified to make some sense to what the test should do.  I have this problem from R1 2013 and still have this issue.  

Though I am not sure if others have had this particular issue happen to them, I would think that this problem causes me as a user to lost the flexibility of having my projects in a convenient location on my computer instead of having to dig through to find it.