Try the Release Candidate 2 for MPS 2017.3!
We are almost there, our final release of MPS 2017.3 is very close. Meanwhile, try the Release Candidate 2 for 2017.3. Some bugs have been fixed but if you find any more please report them to our issue tracker.
Have a nice day!
Yours,
JetBrains MPS Team
The Drive to Develop