I'm currently unable to add custom buttons. Whenever I try to add one, it always requires me to add a thumbnail, and once I try to upload one, I get this error message and then the program crashes.
This happens to me no matter if I'm using a save file or as soon as I load MD up with a blank project. Oh. And this is the error in the bug report:
mvAssert filePath = d:\work\f7c57f528141d59c\marvelous\source\utility\utility.cpp, line = 6437
2D Mode : TRANSFORM_SHAPE
3D Mode : MOVE_OBJECT
stack size: 1, curStackPos: 0
 O class Marvelous::UnReMultipleOperations