Hi,
I was working on a Level blueprint with collision event for a trigger, then I decided to move this behavior to the character. As I disconnected the collision event exec in level blueprint, UE5.6 crashed.
Now I can’t open the level to edit the blueprint, because it crashes. Therefore my project is in standby.
Any ideas?
Cheers
Smokey56.log (118.4 KB)
Hey there @murfinator! Welcome to the community! So it seems like your level blueprint may be corrupted. If you don’t have a backup or source control, we have a couple options.
[2025.09.06-16.19.07:188][101]LogBlueprint: Error: [AssetLog] D:\Unreal Projects\Smokey56\Content\Levels\Level_Game.umap: [Compiler] ICE: The type of property /Script/CoreUObject:Default__ObjectProperty doesn't match the terminal type for pin Interface .
and
[2025.09.06-16.19.07:190][101]LogWindows: Error: appError called: Assertion failed: Pair != nullptr [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Map.h] [Line: 729]
These errors likely mean that if you don’t have a backup of that map, you may not be able to save it. So first, we’re going to see if there is a backup of the map that got autosaved.
First, as I always recommend, close the engine and back up your project folder.
Check in your \Unreal Projects\YourProjectName\Saved\Autosaves folder to see if the umap file got backed up. If it did, replace the broken one with the backup and see if the project will launch.
If not, we’re going to have to bypass loading into the damaged map to salvage the remaining project.
Open Unreal Projects\YourProjectName\Config\DefaultEngine.ini with your IDE or notepad of choice. Find the EditorStartupMap entry, It will look a bit like this:
[/Script/EngineSettings.GameMapsSettings]
EditorStartupMap=/Game/ThirdPerson/Maps/ThirdPersonMap.ThirdPersonMap
GameDefaultMap=/Game/ThirdPerson/Maps/ThirdPersonMap.ThirdPersonMap
You will have to point it to another valid map in your project. Left blank it may launch to a blank map, but I’m not certain on that.
In the future I recommend using some form of source control like Perforce or Git to keep backups and restore points of the project.
Let me know how it goes!
Hi, thanks for replying!
Unfortunately there is no autosave folder.
Also, my project already opens in a blank level. Its when I open the corrupted level that it crashes. So I do have access to UE, I just can’t open the level bp to fix it without opening the level.
Ahh that’s unfortunate. There isn’t a native method to be able to access the Level Blueprint without loading (thus crashing) the level. Without the autosave, there isn’t too many options remaining that wouldn’t be more effort than remaking the map.
Ah that’s sad. I wonder what caused it so I can at least avoid it in the future. Maybe best option is to downgrade to 5.4? Only issue is I have a bunch of 5.6 assets.
5.4 is going to definitely be more stable overall, but this issue is possible in any engine version. Source control can help mitigate any damage when things like this occur. If the engine crashes during any saving action, whatever asset that was being written to can be corrupted. Even a local source control would be good to keep on hand for these situations.