Unreal Engine Issues

Issue with Niagara emitter inheritance

Modules in the particle spawn stage get unlocked and lose inheritance after changing the inherited emitter's interpolated spawn mode to "No Interpolation" then resetting. ...

Niagara problem with "Static Mesh Location" module

Niagara crash when using a particle attribute reader that has been passed around between modules

The following Niagara usage pattern results in either a crash or in incorrect data being read from a Particle Attribute Reader: Emitter Spawn Stage – A module has an Attribute Reader input specifie ...

Intermittent Content is Missing from Cook errors for objects with Niagara packages

Intermittently when cooking large licensee projects, an error is reported at the end of the cook:LogCook: Error: Content is missing from cook. Source package referenced an object in target package b ...

Heterogeneous Volume Actor causes ensures to trigger in Debug builds

When 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 ...

Niagara Data Interface "Errors and Warning" section on Module Details not updating when error messages change

This is a regression: it worked correctly up to UE 5.5, but not in 5.6 or mainline latest. Possibly caused by CL 40093049. Class UNiagaraDataInterface provides virtual method GetFeedback(), which a ...

Vector VM - Crash / memory stomp when using > 255 external function calls

The 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 ...

FNiagaraStackGraphUtilities::FindScriptModulesInStack() parameter "OutFunctionCalls" should be a reference

On file [Engine\Plugins\FX\Niagara\Source\NiagaraEditor\Public\ViewModels\Stack\NiagaraStackGraphUtilities.h], function FNiagaraStackGraphUtilities::FindScriptModulesInStack() receives a parameter " ...

Niagara Regression - Looping particle with Spawn Burst Instantaneous on time 0.0 flickers for a frame between loops

Note: 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

When 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. ...