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 ...
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 ...
[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 ...
Vector VM - Crash / memory stomp when using > 255 external function calls
UE - Niagara - Aug 12, 2025The Vector VM has only every supported a byte's worth of external function calls, when we blew the limit it would index into the incorrect VM call. The new VM will also overwrite memory when exceed ...
Duplicating / Moving (to another level) an actor with a Hierarchical Instanced Static Mesh component causes a crash
UE - Graphics Features - Nov 14, 2016When you have an actor with a Hierarchical Instanced Static Mesh component that has a Static Mesh set and is populated with at least 1 instance and then duplicate it or move it to another level, it ...