Unable to perform database compare

Question

Recently, not since three or four days, we have been facing an issue when trying to compare within visual studio 2013 on a database project. The compare screen loads up but I'm not able to select source or target. Nothing happens if I click the target combo
and select "Select target...". Sa for source. I tried using the menu bar's "SQL" with the compare screen open and tries "Select Target" from there only to be presented with a error message: An item with the same key has already
been added. Same behaviour on source.
We tried reading the logs of visual studio, searched all over internet and got suggestion to update SSDT but thats not really an option as the search results are from 2011/2012 and those update don't exists or apply to VS2013.
We did more testing:
A stand-alone new solution with new DB projects works fine
Loading our DB project directly into a new solution works fine
Our full solution 'A' fails.
Other of our solutions 'B' and 'C' also fails
Couldn't find anything in the solution file that could prevent comparing.
Anyone facing/had similar issues?
Regards, Hassan Gulzar

Answer 1

Hi Hassan,
We will have an update for SSDT in VS 2013 early next week for you to install, but this issue doesn't sound familiar.  We did have a schema compare bug where we had odd behavior if you had your DPI set at 125%+, but that was fixed for VS 2013 RTM. 
Are you on VS2013 RTM with the SSDT that came as part of that install?
To help us debug, can you please turn on tracing and send me your logs.  jillth @ Microsoft .com
For diagnostic purposes we would like you to gather an event log for the issue that
you are experiencing in SSDT. In order to gather a log and send it to a member
of the team, please follow the steps below.
Open a new command prompt as Administrator.
Run the following command
logman create trace -n DacFxDebug -p "Microsoft-SQLServerDataTools" 0x800 -o "%LOCALAPPDATA%\DacFxDebug.etl" -ets
logman create trace -n SSDTDebug -p "Microsoft-SQLServerDataToolsVS" 0x800 -o "%LOCALAPPDATA%\SSDTDebug.etl" -ets
Run whatever the target/issue scenario is in SSDT.
Go back to the command prompt and run the following commands
logman stop DacFxDebug -ets
logman stop SSDTDebug -ets
The resulting ETL files will be located at %LOCALAPPDATA%\SSDTDebug.etl &  %LOCALAPPDATA%\DacFxDebug.etl
and can be navigated to using Windows Explorer.
Please attach this file to an email and send it to the SSDT team member you have been working with
NOTE - These logs will only be used by Microsoft product team members in order to better diagnose the problem you are experiencing with SSDT and
will not be shared elsewhere. If you want to make
sure that there is no private information in your ETL file, the SSDTDebug.etl file can be opened and analyzed using the Windows Event Viewer.
To do this, open the Windows Event Viewer application. In the right-hand panel,
select Open Saved Log. Navigate to the location where you saved the log, open,
and review the contents of the trace.