Unreal Engine Issues
Unreal Engine Issues
High framerates result in desyncs with clients when using a dedicated server.
UE - Networking - Apr 17, 2019When a client operates at a high framerate on a dedicated server, their player movement will become desynced with the server. This manifests in different ways on different versions. In 4.21, it caus ...
Launching on IOS, sessions do not appear in the Session Frontend
UE - Networking - Oct 17, 2018Licensee reports: Dug into this further and our iOS devices aren't receiving any of the handshake messages sent by the Session Frontend (or any other UDP messages for that matter) because multicast ...
World Partition - Deleted actors can become unloaded prior to saving
UE - World Creation - Worldbuilding Tools - World Partition - Apr 11, 2025In world partition levels, deleted actors can become unexpectedly unloaded prior to saving, causing loss of work. Specifically, this issue occurs after the undo history has been cleared (either manu ...
Control Rig: crashes when compiling after rearranging input pins in an array in Example Rig Unit
OLD - Anim - Aug 20, 2019The crash doesn't occur every time, but it will happen within 3 swap and compiles in my experience. I got multiple different callstacks when I cause the crash using the reproduction steps (they are ...
Incorrect Velocity Calculation at Animation Sequence Transitions in Level Sequence
UE - Anim - Sequencer - Feb 18, 2025When adding an Animation Track to a Level Sequence and placing Animation Sequences back-to-back without gaps, the velocity can be miscalculated at the transition between sequences. This issue occur ...
Large Landscapes cause long PIE start time delays
UE - LD & Modeling - Terrain - Landscape - Jan 29, 2020These delays appear with large Landscapes (for example 8029 x 8029) . The delays only start occurring after the level is saved and reopened. After which PIE start times will be 5 to 15 times longer ...
[CrashReport] Assertion failed: !bRequireNormalization - UE4Editor_Landscape!ULandscapeComponent::ReplaceLayer()
UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017This is a common crash affecting users in 4.16, and has occurred since at least 4.14. Over 200 unique users have been affected, though they have provided little information. User DescriptionsI am a ...
Templated enum GetValueAsString function returns incorrectly formatted string
UE - CoreTech - Aug 19, 2020For many years there has been a static function on UEnum called GetValueAsString which would convert an enum like EAttachmentRule::KeepWorld to the string "KeepWorld", if you passed in the explicit ...
Project configured to spawn Niagara system via Character blueprint in a Code project fails to Cook, then crashes project on open
UE - Niagara - Mar 7, 2019Project configured to spawn Niagara system via Character blueprint in a Code project fails to Cook, then crashes project on open Discovered when verifying [Link Removed] (also similar to [Link Remo ...
Paper2D performance regression due to TArray resizing
UE - Graphics Features - Aug 16, 2019We've noticed after upgrading our heavy Paper2D project to 4.22 that tilemap performance has been massively degraded compared to previous versions. After some digging we found out that it's due to a ...