This just saved me a huge headache, thanks! I think I found a bug in UE 5.0.3 where with some combination of World Partition + level Blueprint referencing an editor only actor the editor was crashing when I’d open the level. To fix I used @Friend_of_Ants’s approach to search for something I knew was in the level BP, opened it, removed the bad reference, and then I could open the level.
For searchability, the logs for this crash were:
Assertion failed: Pair != nullptr [File:D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Map.h] [Line: 656]
A breakpoint instruction (__debugbreak() statement or a similar call) was executed in UnrealEditor-Win64-DebugGame.exe.
Exception thrown: read access violation.
ActorDescView was 0x10.
The last frame in the Call Stack was:
UnrealEditor-Engine.dll!FWorldPartitionStreamingGenerator::ValidateActorDescriptorViews