Steps to reproduce:
1) Open up the map editor (I only tested in iso mode)
2) Right click an object on the map to bring up the popup menu.
3) Click + or - while the popup is open. Dream Maker will crash.

There isn't much else of a way to describe it. This doesn't happen with the Shift+-> etc. shortcuts, because the arrow keys control your standard right click menus. Also, the nudge shortcuts still work, just not with the menu up.

This has been bugging me since v455.1043, please fix it soon!