Level Streaming Assertion - How to backtrack a generated package

JesseyCool
Tue, 03 Mar 2026 09:33:44 +0000
World Creation

Hello,

Using Unreal Engine 5.6.1

My question:
How to backtrack a generated package with a from the Level Streaming warning, to something in the project?

LogLevelStreaming: Warning: Couldn’t find ULevel object in package ‘/Game/DucksideGame/Levels/MainlandLevel/Generated/BZQ7WEHHY832V75H3PQX02CNB’

Right after it triggers this assertion:
Assertion failed: CurrentState == ELevelStreamingState::Removed || CurrentState == ELevelStreamingState::Unloaded [File:/Engine/Private/LevelStreaming.cpp] [Line: 2432]

Full log with LogStreaming=Verbose (https://www.reddit.com/r/unrealengine/comments/790nrp/tip_verbose_stream_logging/):

LogLevelStreaming: Warning: Couldn’t find ULevel object in package ‘/Game/DucksideGame/Levels/MainlandLevel/Generated/BZQ7WEHHY832V75H3PQX02CNB’
LogStreaming: Verbose: GameThread: LoadCompleted: /Game/DucksideGame/Levels/MainlandLevel/Generated/75QV4C8Y2E87N87CG1WGOJIFL (0xABFB9A734B3A56E7) /Game/DucksideGame/Levels/MainlandLevel/Generated/75QV4C8Y2E87N87CG1WGOJIFL (0xABFB9A734B3A56E7) - All loading of package is done, and the async package and load request will be deleted.
LogStreaming: Verbose: GameThread: LoadCompleted: /Game/DucksideGame/Levels/MainlandLevel/Generated/DTQRDE8R6QNYVL7DD979MYOM9 (0x1B0964D4FC74E8E3) /Game/DucksideGame/Levels/MainlandLevel/Generated/DTQRDE8R6QNYVL7DD979MYOM9 (0x1B0964D4FC74E8E3) - All loading of package is done, and the async package and load request will be deleted.
LogStreaming: Verbose: GameThread: LoadCompleted: /Game/DucksideGame/Environment/GeodeBiome/POIs/Marketplace/SM_CrateFilling_B (0x4A8992808CB07E60) /Game/DucksideGame/Environment/GeodeBiome/POIs/Marketplace/SM_CrateFilling_B (0x4A8992808CB07E60) - All loading of package is done, and the async package and load request will be deleted.
LogStreaming: Verbose: GameThread: LoadCompleted: /Game/DucksideGame/Levels/MainlandLevel/Generated/3MY3U9KDF0HYQ9KOL614XN3PP (0x8A9E2B3E95A87F67) /Game/DucksideGame/Levels/MainlandLevel/Generated/3MY3U9KDF0HYQ9KOL614XN3PP (0x8A9E2B3E95A87F67) - All loading of package is done, and the async package and load request will be deleted.
LogStreaming: Verbose: GameThread: LoadCompleted: /Game/DucksideGame/Characters/Player/Materials/Textures/T_DougSummer_C (0x276C2E8CC954EEFA) /Game/DucksideGame/Characters/Player/Materials/Textures/T_DougSummer_C (0x276C2E8CC954EEFA) - All loading of package is done, and the async package and load request will be deleted.
LogStreaming: Verbose: AsyncThread: Deleted: /Game/DucksideGame/Levels/MainlandLevel/Generated/BZQ7WEHHY832V75H3PQX02CNB (0xF7E132E140C39489) /Game/DucksideGame/Levels/MainlandLevel/Generated/BZQ7WEHHY832V75H3PQX02CNB (0xF7E132E140C39489) - Package deleted.
LogStreaming: Verbose: AsyncThread: Deleted: /Game/DucksideGame/Data/Quests/MainlandAreaQuests/Errands/Racing/BP_LaunchGeode (0x5ECD8A65D023CA3C) /Game/DucksideGame/Data/Quests/MainlandAreaQuests/Errands/Racing/BP_LaunchGeode (0x5ECD8A65D023CA3C) - Package deleted.
LogStreaming: Verbose: AsyncThread: Deleted: /Game/DucksideGame/Levels/MainlandLevel/Generated/75QV4C8Y2E87N87CG1WGOJIFL (0xABFB9A734B3A56E7) /Game/DucksideGame/Levels/MainlandLevel/Generated/75QV4C8Y2E87N87CG1WGOJIFL (0xABFB9A734B3A56E7) - Package deleted.
LogStreaming: Verbose: AsyncThread: Deleted: /Game/DucksideGame/Levels/MainlandLevel/Generated/DTQRDE8R6QNYVL7DD979MYOM9 (0x1B0964D4FC74E8E3) /Game/DucksideGame/Levels/MainlandLevel/Generated/DTQRDE8R6QNYVL7DD979MYOM9 (0x1B0964D4FC74E8E3) - Package deleted.
LogStreaming: Verbose: AsyncThread: Deleted: /Game/DucksideGame/Environment/GeodeBiome/POIs/Marketplace/SM_CrateFilling_B (0x4A8992808CB07E60) /Game/DucksideGame/Environment/GeodeBiome/POIs/Marketplace/SM_CrateFilling_B (0x4A8992808CB07E60) - Package deleted.
LogStreaming: Verbose: AsyncThread: Deleted: /Game/DucksideGame/Levels/MainlandLevel/Generated/3MY3U9KDF0HYQ9KOL614XN3PP (0x8A9E2B3E95A87F67) /Game/DucksideGame/Levels/MainlandLevel/Generated/3MY3U9KDF0HYQ9KOL614XN3PP (0x8A9E2B3E95A87F67) - Package deleted.
LogOutputDevice: Warning:

Script Stack (0 frames) :

Assertion failed: CurrentState == ELevelStreamingState::Removed || CurrentState == ELevelStreamingState::Unloaded [File:.\Runtime/Engine/Private/LevelStreaming.cpp] [Line: 2432]

I did make a build with a custom engine including this pull request (as a temporary fix):

UE 5.6 World Partition – Level streaming causes crash in packaged build World Creation

My fix is https://github.com/EpicGames/UnrealEngine/pull/14287 for ue5-main.

But I feel like this is an issue in our project and not an Unreal Engine issue per se. That is why I want to track down where it is coming from.

Thank you.

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