Unreal Engine Issues
Unreal Engine Issues
Using ConstructorHelpers::FClassFinder in a GameMode constructor may result in a default value or crash if the level is reloaded multiple times.
UE - Gameplay - Oct 27, 2015Randomly selecting a character class from the GameMode constructor using ConstructorHelpers::FClassFinder can result in default or null character being set when the level is reloaded. It appears tha ...
Server crashes when client connects after Server has reloaded a sublevel with a deleted actor
UE - Networking - Jul 13, 2017UNetDriver::DestroyedStartupOrDormantActors maintains a list of deleted startup (and dormant) actors. This is used to notify clients that have joined the server of Actors that need to be destroyed ...
Out-of-Bounds Access During Partial Updates of ISMC Per-Instance Custom Data
UE - Graphics Features - Jan 6, 2026When using instance custom data values, removing an instance and changing the number of custom data floats in sequence can cause an array-out-of-bounds crash. The underlying arrays are not resized ...
Sequential Level Loading in Python causes Crash
UE - Editor - Workflow Systems - Apr 16, 2019Loading all the levels selected in the Content Browser and running the aforementioned Python script causes the editor to crash Tested in 4.20.3 (CL - 4369336), 4.21.2 (CL - 4753647), 4.22 (CL - 5 ...
Client crash on seamless travel in DataReplication with lag
UE - Networking - Jan 11, 2016When server traveling, client may crash due to lag while attempting to replicate object/property. ...
Virtual Bone caused nanite skinned mesh crash
UE - Graphics Features - Nanite - May 31, 2025When a Nanite skeletal mesh has a virtual bone the engine can crash when changing LODs ...
Assertion failed: PlatformNeedsExtraDeletionLatency()
UE - Rendering - Architecture - RHI - Mar 5, 2019Animating a HISM along a spline when many other HISMs are present will result in a crash in 4.22. Confirmed in 4.23 MAIN @ CL 5291468 ...
After Seamless Server Travel, the Client cannot move the character or see the Server character
UE - Networking - Jul 9, 2015After Seamless Server Travel, the Client cannot move the character or see the Server character. On the Server, the Client character appears to be falling in place. Tested in both first and third per ...
Making changes to a Camera Shake while previewing the Camera Shake triggers a crash
UE - Anim - Sequencer - May 23, 2022This is not a regression. Tested in //UE4/Release-4.27 CL 18319896 Making changes to a Camera Shake while previewing the Camera Shake triggers an Assertion upon compiling. ...
Crash when deleting the Add Component By Class node after changing the Relative Transform of the component
UE - Gameplay - Blueprint - Mar 31, 2021When adding the Add Component By Class node, choosing a class that has a Relative Transform pin, changing the transform, and deleting the node the editor crashes. I tested this with the Skeletal Mes ...