World Partion Crash [Solved]

[Chaqi-1 (Chaqi-)]

Hello, after moving away from the starting point of the game, I keep getting this crash while restarting the game, the game becomes unplayable after crashing.

Assertion failed: !FindObject<UPackage>(nullptr, *PackageName) [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartitionLevelHelper.cpp] [Line: 260]

UnrealEditor_Engine!FWorldPartitionLevelHelper::CreateEmptyLevelForRuntimeCell() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartitionLevelHelper.cpp:260]
UnrealEditor_Engine!UWorldPartitionLevelStreamingDynamic::CreateRuntimeLevel() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartitionLevelStreamingDynamic.cpp:153]
UnrealEditor_Engine!UWorldPartitionLevelStreamingDynamic::RequestLevel() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\WorldPartition\WorldPartitionLevelStreamingDynamic.cpp:261]
UnrealEditor_Engine!<lambda_b704a7c45d1ac7686c4ae34f0c8d423f>::operator()() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\LevelStreaming.cpp:829]
UnrealEditor_Engine!ULevelStreaming::UpdateStreamingState() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\LevelStreaming.cpp:1054]
UnrealEditor_Engine!UWorld::UpdateLevelStreaming() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\World.cpp:3907]
UnrealEditor_Engine!UWorld::BlockTillLevelStreamingCompleted() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\World.cpp:3812]
UnrealEditor_Engine!UEngine::BlockTillLevelStreamingCompleted() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\UnrealEngine.cpp:14961]
UnrealEditor_Engine!UGameInstance::StartPlayInEditorGameInstance() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\GameInstance.cpp:530]
UnrealEditor_UnrealEd!UEditorEngine::CreateInnerProcessPIEGameInstance() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:3210]
UnrealEditor_UnrealEd!UEditorEngine::OnLoginPIEComplete_Deferred() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:1673]
UnrealEditor_UnrealEd!UEditorEngine::CreateNewPlayInEditorInstance() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:1936]
UnrealEditor_UnrealEd!UEditorEngine::StartPlayInEditorSession() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:2941]
UnrealEditor_UnrealEd!UEditorEngine::StartQueuedPlaySessionRequestImpl() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:1250]
UnrealEditor_UnrealEd!UEditorEngine::StartQueuedPlaySessionRequest() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:1153]
UnrealEditor_UnrealEd!UEditorEngine::Tick() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\EditorEngine.cpp:1777]
UnrealEditor_UnrealEd!UUnrealEdEngine::Tick() [D:\build\++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\UnrealEdEngine.cpp:517]
UnrealEditor!FEngineLoop::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5369]
UnrealEditor!GuardedMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:202]
UnrealEditor!GuardedMainWrapper() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:107]
UnrealEditor!LaunchWindowsStartup() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:244]
UnrealEditor!WinMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:282]
UnrealEditor!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

[Solution]

Player Start Points checked “Is Spatially Loaded”. “ChoosePlayerStart” function return null, when world started and this cause crash

[Mildanach]

I have exact crash, but after loading game state with Easy Multi Save and moving the player. What exactly did you do to solve this?

[Chaqi-1 (Chaqi-)]

Un check “Is Spatially Loaded” at Player Starts. I’m override “ChoosePlayerStart” function to set which “player start” saved in Save Object. Game Mode sets “Player Start” to Empty because World Partition does not finish loading “Player Start” when the game starts to load, so it gives Nullptr error.

This is a general problem. When the game starts to access or manipulate an object, World Partition gives this error if it hasn’t loaded that object yet. You need to wait for World Partition to finish loading or untick “Is Spatially Loaded”. I couldn’t find saying wait for World Partition either.

[Massive_LDZ]

I was looking for a reason why I can’t save and then load actors that are on an unloaded chunk in the world partition. I kept having an engine crash with a similar error to yours. I was already very broken because I couldn’t find a solution anywhere, I was lost because I thought it was the fault of the save system that does not work with unloaded World Partition chunks. Luckily I found your post. You are a hero!
Anyone who tried to combine world partition with Easy Multi Save - It works, I had to check the player start checkbox “Is Spatially Loaded” to true as my friend wrote in the post above. Thanks again!