Hot reload causes placed actor to lose variable references

UE - Foundation - Cpp Tools - Hot Reload - Nov 9, 2017

Preforming a hot reload causes placed actors to lose code based variable settings. More repro steps: 1. Open UE4Editor.exe 2. Create a First Person Code project 3. Build the project for Developme ...

AddOrUpdateWarpTargetFromComponent behaving incorrectly when using a SceneComponent with non-identity scale

UE - Anim - Gameplay - Jul 15, 2025

When using AddOrUpdateWarpTargetFromComponent you can pass in a SceneComponent, Relative Location and Rotation as well as optionally choosing to have the warp target follow the object if it moves.If ...

Assertion failed in FAudioDevice::UnregisterSoundClass when GC

UE - Audio - Aug 13, 2018

The licensee reported that check(IsInAudioThread()) was failed in FAudioDevice::UnregisterSoundClass when GC. The following is the call stack: 1 #00 pc 030d7b58 libUE4.so HandleError (/home/pirates ...

[CrashReport] FMacWindow::ApplySizeAndModeChanges | SWindow::Resize()

UE - Platform - Apple - Nov 21, 2017

This is an infrequent Mac crash in the 4.18 release. The callstack is similar to [Link Removed] and originally thought to be part of the same issue, but that Jira has been fixed and many other simi ...

Auto-Save failing, pulling old saves and blocks users from continuing

UE - Editor - Workflow Systems - May 15, 2023

Reporting an issue where are users are getting prompted to auto-save, but then it appears to fail and asks them to manually save. They're being prompted with outdated save files, but get stuck in a ...

Property Editors fail to import text values for FKeys within array/set/map containers when the key is identified by some valid non-alphanumeric characters

UE - Gameplay - Input - Oct 28, 2024

The FKey structure represents a user action input such as a keyboard key, a mouse button/wheel, or a gesture in VR. For the keyboard, it can represent any pressable key, such as letters, numbers, sy ...

Exception on missing fiile during GC in horde storage

UE - Foundation - Horde - Storage - May 7, 2025

During GC, if a file was manually deleted (but the storage system is still track), GC can erroneously fail (and never remove the reference). This causes a backup in GC, putting the whole algorithm i ...

[CrashReport] Mac crash - UE4Editor-Slate.dylib!FSlateEditableTextLayout::FTextInputMethodContext::GetSelectionRange()

UE - Platform - Apple - Aug 15, 2017

This is a trending Mac crash coming out of the 4.17.0 release, but also seems to have occurred in 4.16. Users have not provided any descriptions of their actions when the crash occurred. The callst ...

Crash when opening a texture or editing its properties after stopping a preview in the material editor

UE - Rendering Architecture - Materials - Sep 5, 2025

When a texture asset has certain properties edited, its PostEditChangeProperty() method calls to UTexture::NotifyMaterials(), which triggers a recompilation of materials that reference it in their m ...

Sequencer frame range progression is not continuous

UE - Anim - Sequencer - Oct 28, 2021

The end of the level visibility section places a DeterminismFence. This causes the issue. The fence clips the frame range and produces a discontinuous frame ranges, e.g. 23201~24000, then 24001~24 ...