Same but i installed the editor about 2 months ago that was bugged and actually crashed.
I believe the version im running is… 1375.
The odd thing is vs 2017 still opens it and uses the new tool of course.
On the other hand i can switch the .mgcb to be opened with other applications in vs2019 and they work.
I should try to dl a new version but if it screws up i don’t feel like messing with it right now i have a feeling its just because this version is messed up but no one else has told me they can actually double click a mgcb file in vs2019 solution explorer and it will open so i guess i wont be sure till i try a newer copy.