It didn't crash on me, but I had to remove the nodes in my umg blueprint and readd them every time I added some new functionality to it. Maybe I should have created all the button click events at the same time, but I did a button at a time and everytime the menu would break on me. Also I tried to create a new game quit game screen then in another blank level a character select screen. That wasn't working at all it seems like every time I loaded the new level in the editor to work on that widget that it would break. Eventually instead of doing it in two levels I removed all the widgets then re-added the second set of widgets, instead of loading a new level to do the character select screen. That seemed to work better but my blueprints were still breaking.