After merging the solution file while getting the latest version and checking back in, the TFS automatic build triggered by the check-in failed.
The solution was quite simple:
- I added a dummy file to the solution and checked-in the solution with the new dummy file.
- I had a successful automatic build.
- I removed the dummy file and checked-in again the solution without the dummy file.
- I had another successful automatic build.
I hope this will help others too!