Unreal Engine Issues
Unreal Engine Issues
Paper2D: Editor hangs when assigning Sprite Atlas Group to Sprite
UE - Gameplay - Paper2D - Dec 16, 2025In UE 5.3 and later, assigning a Sprite Atlas Group to a UPaperSprite asset can cause the editor to hang and eventually crash. This behavior has been reproduced in 5.3, 5.6, and a recent UE5-main so ...
[Stream Cache][Assert] - UnrealEditor_Engine!FCachedAudioStreamingManager::RemoveReferenceToChunk() [AudioStreamingCache.cpp:701]
UE - Audio - Mar 12, 2024Found while messing around with a revamp of some of the Audio Stream cache tests. The map in this test is a WIP as I'm still just trying stuff out, but hit this assert 5/5 times.Assertion failed: Fo ...
[CrashReport] UE4Editor_SlateCore!FHittestGrid::GetBubblePath() [hittestgrid.cpp:145]
UE - Editor - UI Systems - Slate - Oct 27, 2017This is a trending crash coming out of the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. Based on the affected project names, this crash seems co ...
Crash in RHICommandContext& GetContext() in Test/Shipping builds when bUseChecksInShipping is true
UE - Rendering - Architecture - RHI - Nov 29, 2022RHIinit() calls GRHICommandList.GetImmediateCommandList().GetContext() to make sure that GDynamicRHI->Init() initialized the immediate command list (by calling FRHICommandListImmediate::InitializeIm ...
[CrashReport] UE4Editor_Kismet!FFindInBlueprintSearchManager::OnCacheAllUncachedBlueprints() [findinblueprintmanager.cpp:2095]
UE - Gameplay - Blueprint - Nov 2, 2017This is a trending crash coming out of 4.18; it may be a regression. Users have not provided any descriptions of their actions when the crash occurred. Source Context 2093 // Start the cac ...
Behavior Tree (BT) services added to root nodes call the initial tick twice
UE - AI - Nov 20, 2024Behavior Tree (BT) services added to root nodes call the initial tick twice A BT Service with the setting "Call Tick on Search Start" enabled will execute the initial tick twice when added to the ro ...
FNiagaraScalabilityManager incorrectly reactivates a NiagaraComponent that was deactivated by runtime user code
UE - Niagara - Scalability - Oct 1, 2025Context: The Niagara System is the primary tool to do visual effects inside Unreal. Niagara systems can be culled due to distance. Problem: Once a deactivated Niagara System is culled due to distan ...
[CrashReport] Failed assert during BP compilation (trying to call a default delegate) (UE4Editor_KismetCompiler!FScriptBuilderBase::EmitFunctionCall() [kismetcompilervmbackend.cpp:1216])
UE - Gameplay - Oct 27, 2017This is a trending crash coming out of the 4.18 release. User DescriptionsI tried to call an Event Dispatcher (which is assigned in the Level Blueprint) in the Construction Script of the Blueprint ...
[CrashReport] Mac/Metal Intel compiler crash - UE4Editor-MetalRHI.dylib!CreateMTLRenderPipeline()
UE - Graphics Features - Oct 27, 2017Mark S: This is an Intel compiler failure on macOS 10.12.6. Callstack from LogAssertion failed: [File:/Users/build/Build/++UE4+Release-4.18+Compile/Sync/Engine/Source/Runtime/Apple/MetalRHI/Privat ...
Bug in StringTemplate.cpp related to modulo operator in MaterialTemplate.ush (code fix provided)
UE - Rendering - Architecture - Materials - Jun 25, 2024Shader Template files like MaterialTemplate.ush do not submit previous chunks when encountering a `%` character, unless that `%` character is `%s` or `% {...} `. Because the error is happening ...