Running 4.25 on Windows 7, but I’ve tried this with 4.22, 4.23, and 4.24 as well with the same result. This started in June, but I’ve been doing hardware upgrades so I couldn’t confirm until now that it was the engine’s fault. Seems that something in Windows changed and is now incompatible with UE.
If I have the Desktop Window Manager service enabled, which it is by default, the menus and buttons in the editor stop working. They’re still clickable, but the dropdowns are invisible, do not respond to being clicked, and their tooltips show up as black boxes. I also cannot open assets or anything in a separate window (message log, error messages, etc). It just says there’s a window in my taskbar but it remains a transparent pane and I can never actually look at it. This usually happens after I’ve tested the game, but if I just open a level and wait long enough, it’ll do this as well. It makes the engine unusable. It also seems to be a problem with demos of marketplace assets. If DWM is enabled, those will freeze, though the Task Manager never says they’ve stopped responding.
Is there something I can change in UE to fix this? Currently, I’m just disabling DWM manually, but if it causes problems with packaged demos too, I would rather just fix it from the source so that I can rest assured my games work for other people.