Our game works fine with 4.10.2, crashes in 4.10.3

So, in 4.10.2 our game works fine. I made unfortunate decision to upgrade to 4.10.3 and now our game crashes on this code:

UE4Editor-Engine.dll!UEngine::LoadMap(FWorldContext & WorldContext, FURL URL, UPendingNetGame * Pending, FString & Error) Line 9479 C++
UE4Editor-Engine.dll!UEngine::Browse(FWorldContext & WorldContext, FURL URL, FString & Error) Line 8650 C++
UE4Editor-Engine.dll!UEngine::TickWorldTravel(FWorldContext & Context, float DeltaSeconds) Line 8857 C++
UE4Editor-UnrealEd.dll!UEditorEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 1285 C++
UE4Editor-UnrealEd.dll!UUnrealEdEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 361 C++
UE4Editor.exe!FEngineLoop::Tick() Line 2427 C++
UE4Editor.exe!GuardedMain(const wchar_t * CmdLine, HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, int nCmdShow) Line 142 C++
UE4Editor.exe!WinMain(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * __formal, int nCmdShow) Line 189 C++
[External Code]

which points me at:

// Fixme: hacky but we need to set PackageFlags here if we are in a PIE Context.
// Also, don't add to root when in PIE, since PIE doesn't remove world from root
if (WorldContext.WorldType == EWorldType::PIE)

Also there appears to be no option to downgrade from 4.10.3 to 4.10.2, so that sucks.

Hi Lambda42,

This is a known issue in 4.10.3 hotfix, which crashes game and possibly editor when traveling between maps (UE-27124). We have since fixed this internally, and fix is included in 4.10.4 hotfix which should be released shortly. Let us know if this problem still occurs after updating to 4.10.4. Thanks!

I’m having this issue with 4.12.3, what is causing it and how can I fix it?

This issue has been re-opened, and is being investigated by our developers; however, there is currently no timeline for when a fix will be released.
Have a great day

If anyone else is having this problem and using source code, I did this for a fix until official update.

Engine\Source\Runtime\Engine\Private\UnrealEngine.cpp line 9686 in if statement before check() add:


…seems to work okay for now.

Hi Sean, is there a way I can monitor progress of this bug? it’s causing me a lot of issues and I can’t progress without a fix.

We do not have a way for public to track progress of bug reports at this time; however, I will continue to provide updates on issue as they become available.

Hi Sean, this issue (UE-27124) is still happening in 4.13.0

Hey MikeD,

What are repro steps that you are using when crash occurs? original repro no longer occurs for me in 4.13.0.

Hi Sean,

It really is just clicking Play In Editor from my level, it used to work perfectly, I haven’t made any changes to this level in months as it’s a simple debug UI launch off. Anyway, I’ll try and get something more concrete for you over next few days.

Okay, feel free to come back to thread if you are able to determine a solid repro case.

Thank you!

Hi Mike and Sean,
I have same problem, do you have any further information?

Unfortunately, without a repro case we were unable to get this issue to occur in 4.13. If you have a set of repro steps we can follow, feel free to let me know and I’ll be glad to continue to investigate.