Hi Guys,
yesterday I was working on my game, when the game suddenly crashed. This happens sometimes, but this time it crashes everytime, when I reopen it. I can’t access the project anymore. I checked my autosave folder to recover a backup, but for some reason there is no save file. Can I do anything, to get access to the project again? And what did I do wrong? The last thing I did was changing a parent reference. When I started the simulation, the game crashed. Please help.
If you can’t open the project anymore, you can try changing the default map in the project file. You can open the actual project file with a text editor 
That’s what I get for doing this off the top of my head. It’s in the Engine.ini file
ProjectFolder/Config/Engine.ini
I think just clearing it’s value will do the trick.
I followed your instructions, and I can open the project again now. But when I laod the Scene, the engine still crashes because of an unhandled stack overflow exception. Is there any way to fix that, or is the scene lost now?
Sounds like there’s just too much in the scene. Try reducing the engine scalability before you open it
Still not working 
The last thing I did was to set the parent of a widget to another widget. Then the game crashed. I don’t know if that caused something like an endless loop which causes the stack to overflow
Can you just edit and un-parent the widget?
I found out that it’s acutally the Widget that is causing the problem here. There is no way to open it so I can’t edit it. I tried deleting it, but even that causes Unreal to crash. Is there any way to delete the widget via any project file?
Ok I just found it. I could delete it in the content folder inside the project files. It works fine again. Thank you so much for your help.
