unable to save maps on WE 1.27a/b on classic but can on 1.26a

[EyeCandy]

Specifically my map which is >60 MB. It loads fine, plays fine on both v1.26a and onwards. Even on Reforged, fine for extended periods. When I try to save or even press "save as" WE just exits, no error message.
Reverting Warcraft back to 1.26a is the only way for me to edit/save the map.
Edit: I can save on reforged editor but as everyone knows, that locks it to reforged so defeats the purpose