Unreal Engine Issues
Unreal Engine Issues
Heterogeneous Volume Actor causes ensures to trigger in Debug builds
UE - Niagara - Aug 24, 2025When a heterogeneous volume actor is used with a volume material in a debug build, the following ensures are triggered: Ensure condition failed: UniformBufferValue || EnumHasAnyFlags(AutomaticallyBo ...
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 ...
Niagara Regression - Looping particle with Spawn Burst Instantaneous on time 0.0 flickers for a frame between loops
UE - Niagara - Jul 16, 2025Note: This worked correctly up to UE 5.4, but repros from UE 5.5 up to mainline latest. If a Niagara Emitter is set up with "Spawn Burst Instantaneous" on time 0.0, and the spawned particle(s) have ...
Editor crash when adding mesh renderer elements in Niagara
UE - Niagara - Jul 8, 2025When adding multiple meshes to a Niagara Mesh Renderer Module, a check() will be triggered due to a mismatch in the number of Widgets and the number of Tooltip Widgets. ...
Incorrect NiagaraSystem passed to KillUnusedComponents in ReclaimWorldParticleSystem
UE - Niagara - Jun 10, 2025In UNiagaraComponentPool::ReclaimWorldParticleSystem, the cleanup loop for WorldParticleSystemPools calls KillUnusedComponents with the reclaimed component's NiagaraSystem (Asset) instead of the sys ...
Niagara Scalability Crash When Processing Significance
UE - Niagara - Jun 4, 2025Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...
Updating niagara with Advance Simlation during game pause causes memory leak
UE - Niagara - May 12, 2025When updating the niagara component in AdvanceSimulation with a tick, the memory of the Niagara tag keeps increasing between pause and resume. ...
FX.TestGPUSort fails on Vulkan
UE - Niagara - May 5, 2025“FX.TestGPUSort” fails on both PC Editor and Android with Vulkan RHI. ...
Niagara color picker user parameter preview no longer updates until confirmation
UE - Niagara - Apr 18, 2025Starting with UE 5.4, the Color Picker Tool no longer updates preview values in real time for certain editor windows like Niagara when working with User Parameters. This behavior is a regression fr ...
When a Niagara User Parameter is renamed, mesh bindings on Niagara Mesh Renderers are not updated, and the binding is silently broken
UE - Niagara - Mar 13, 2025In Niagara, Mesh Renderers expose a "Meshes" array for selecting the meshes to be rendered. On each array entry, a property "Mesh Parameter Binding" is available and allows the user to override that ...