Unreal Engine Issues
Unreal Engine Issues
"Assertion failed: NumberOfFreeBits >= 0" on clients that attempt to connect to a server with the -NoPacketHandler option
UE - Networking - Oct 6, 2020With the rework of IP address resolution in 4.25, this assert now occurs. When no packet handler is used, UPendingNetGame::InitNetDriver calls SendInitialJoin() immediately, before async address res ...
Material slot assignment incorrect after mesh reduction completely removes all triangles from a section
When mesh reduction results in a section becoming empty, the material slots are incorrectly assigned. e.g. if section 0 gets removed due to it having no triangles after reduction, then its material ...
XR -ARKit - Tracked Planes are not attached to the real world objects when moving the camera around
UE - Platform - XR - May 22, 2024When the user attempts to place an object on a tracked plane it slides around the environment not staying in the expected place. Using the ARDebugcheck project with the show planes option you can se ...
Sequencer: Camera Lock Breaks After Closing Sequencer and Re-entering PIE
UE - Anim - Sequencer - Oct 9, 2025Viewport camera lock in Sequencer fails to persist correctly after running PIE with Sequencer open, then closing Sequencer and running PIE again. The issue consistently reproduces using the attached ...
Noise Node used in UI Material is rendering Black
UE - Graphics Features - Feb 15, 2016The Noise Node when used in a UI Material is rendering completely black in 4.11. This is a Regression from Behavior in 4.10.2 It looks like the Noise Node (at least form the preview of the noise i ...
Crash on Mac when adding Convex Collision to a mesh converted from a brush
UE - Platform - Apple - Jun 6, 2017This is one of the top Mac crashes occurring in 4.16. Caused by adding Auto Convex Collision to a mesh converted from a brush. Does not occur on Windows. User DescriptionsI was trying to add a conv ...
[CrashReport] ULevel::GetWorldSettings() - UMaterialInstanceThumbnailRenderer::Draw
Tools - Aug 29, 2017This is a common assertion that has occurred since at least 4.14 and affected nearly 100 users. The callstack is similar to [Link Removed], which was marked fixed for 4.14. User DescriptionsUndoi ...
Physics replicates incorrectly on the Client-Side on sloped surfaces
UE - Simulation - Physics - Jul 30, 2019Replicated objects don't behave correctly on the client-side on slopes when not sleeping. By placing two cubes on one another and slightly rotating the bottom one to create a very gentle slope, the ...
LogAudioMixer warning results in a decrease of performance
UE - Audio - May 21, 2020Unable to reproduce. User believes it is directly related to the speaker they are using when it goes into standby mode. If they unplug the speaker, everything runs okay. After receiving the warning ...
UFE: Can't delete custom launch profiles
UE - Editor - UI Systems - Jul 26, 2023The confirmation message will fails spawning with the following messages in the log: [2023.07.25-20.04.01:038][ 0]LogWindows: Error: Failed to create dialog. The specified resource type cannot be ...