This bug is very easy to reproduce and is caused by the summoning of the copy/paste context menu when right clicking on a UMG widget in a standalone build while in full screen…
To reproduce start a blank project, create a UMG text entry box widget (any UMG widget that allows text entry should work). Have this displayed on screen. Now either run as a standalone ‘or’ build and run the standalone, make the game full screen and now right click. The game will usually crash but sometimes forces the game into windowed mode or to minimize.
I’d also like to sneak in an easy-to-implement suggestion and have the option to disable the right click context menu all together as the context menu is always in “default” UE4 format and breaks the flow of the ui.
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