Ensure in APlayerState::OnRep_bIsInactive may be hit

UE - Networking - Jan 6, 2021

The ensure in APlayerState::OnRep_bIsInactive may be hit due to the player state being replicated before the game state. The check is necessary for making sure the game state is available, but the e ...

Cascade particle system crash when changing levels in a cooked game

UE - Niagara - Jan 6, 2021

Changing levels with an auto-released particle system will cause cooked builds to crash. This is a regression. This crash does not occur in 4.25 ...

Cannot create FBXEportOption in blueprints

UE - Anim - Sequencer - Jan 5, 2021

The class UFbxExportOption is not specified as a blueprint type, so it cannot be constructed in blueprints. This class is needed for exporting FBX files from a sequence, which means this functionali ...

Crash when using automated groom import

UE - Editor - Content Pipeline - Import and Export - Jan 5, 2021

UDN customer reported that using automated groom import through Blueprint was crashing. This can probably be reproduced with a Python script using an asset import task with the automated flag set to ...

Crash occurs when compiling in Editor after editing a C++ file

UE - Foundation - Cpp Tools - Hot Reload - Jan 5, 2021

Crash seems inconsistent, doesn't seem to happen every time. You may have to change the variables and re-compile through the editor a few times to get it to trigger. The crash did occur for me when ...

Granular Synth crashes project when played in standalone or packaged with assertion failure

UE - Audio - Jan 5, 2021

Assertion failed: SoundWave->GetPrecacheState() == ESoundWavePrecacheState::InProgress The above assertion fail was seen when played in standalone mode. Play-In-Editor mode (PIE) is working as exp ...

If use with mesh particles or use with niagara mesh particles is checked in the Usage flag of the material and the material domain is set to volume, compile error will occur.

UE - Niagara - Jan 5, 2021

[SM5] /Engine/Private/VolumetricCloud.usf(118,33-53): error X3018: invalid subscript 'VertexId' This is happening in VolumetricCloud.usf, but it seems that I can avoid the error by adding the follow ...

Duplicate level collections not being respected by UGameEngine::NetworkRemapPath

UE - Networking - Jan 5, 2021

When NetworkRemapPath was refactored in 4.26 to support replay connections via the rep graph, the check for duplicate level id on the driver was lost in the new code path. This causes the demo driv ...

Nameclash error when importing skeletal mesh

UE - Editor - Content Pipeline - Import and Export - Jan 5, 2021

The attached FBX file is getting a nameclash error when imported.  This content is licensee content please delete after using. This issue is NOT occurring at 4.25.4 Binary @ CL 14818863 Marked as ...

WaitMutex behaves poorly when there are casing differences in the same path

UE - Foundation - Cpp Tools - UnrealBuildTool - Jan 5, 2021

The proposed solution here is to make the casing of the path provided to the hashing function for the mutex consistent with something like:publicstatic string GetUniqueMutexForPath(string Name, stri ...