Unreal Engine Issues
Unreal Engine Issues
FMath::TruncToInt() may result in incorrect data being returned in instances when a Double is passed in containing a large integer value
UE - Foundation - Core - Aug 4, 2016The FMath::TruncToInt() function takes a float parameter, but some calls to this function pass in a double value. For most use cases, this will probably work fine. However, if the integer values are ...
Random Number Generated in Constructor Returning Different Value on Begin Play
UE - Gameplay - Jan 13, 2016When generating a random number using FMath::RandHelper() in the constructor of an actor, attempting to print that same number on BeginPlay returns a different value than the constructor. However, ...
Crash when using StaticDuplicateObject with mismathced Source and Destination class types
UE - Foundation - Jun 19, 2025Starting in Unreal Engine 5.4, StaticDuplicateObject internally switched to using Unversioned Property Serialization (UPS) for performance reasons. However, UPS assumes the source and destination ob ...
Set Actor Scale 3D Not Functioning as Expected
UE - Gameplay - Blueprint - Jan 12, 2016Using Set Actor Scale 3D in the Construction Script is not functioning as expected. If you set the scale to 1,1,1, you are still able to freely scale an instance of the object in the scene. However, ...
Using multiple SceneCapture2D with DLSS Enabled crashes UE
UE - Rendering - Graphics Features - Nov 22, 2024A licensee is reporting a crash (or rather a check fail) in Sceneview.cpp which happens with when a SceneCapture2D is used with DLSS enabled. He has a fix, and wants to share it with us for integrat ...
Switching to different modes in the Modes panel causes PIE to take input from a connected VR headset for the Y axis camera movement
UE - Platform - XR - Dec 9, 2016If a VR headset is connected, it will be used for Y axis camera input in PIE if you have switched to and from the Landscape tab in the Modes panel. You can fix this temporarily by reopening the edit ...
Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection
UE - Rendering - Architecture - May 30, 2025Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection (Experimental in 5.6). The licensee describes their crash, their analysis, and a proposed fix: This crash ...
Getting a TextBlock variable from the Return Value of a Create Widget node inside a Player Controller will cancel all the nodes before it in Standalone
UE - Gameplay - Blueprint - May 15, 2015Getting a TextBlock variable from the Return Value of a Create Widget node inside a Player Controller will cancel all the nodes before it in Standalone. Does not occur in other PIE modes, and does n ...
[CrashReport] Tutorial crash UObject::execLetValueOnPersistentFrame()
UE - Gameplay - Blueprint - Jul 7, 2017This is another Tutorial crash that shares a similar callstack with [Link Removed] and [Link Removed], but those specific repro steps have been fixed while this one is still occurring in 4.16.2. On ...
Huge performance hit when recording a demo (demorec)
UE - Networking - Jun 3, 2019The current engine version (4.22) seems to suffer a huge performance hit when using the demo recording (demorec) feature. This issue is present in both the editor and the packaged game (developer bu ...