Unreal Engine Issues

Importing static mesh while a PIE session is running permanently breaks nanite on the asset

Importing a Static Mesh during PIE can cause it to never enable Nanite, even if it reports that Nanite is enabled. To re-enable Nanite on the mesh, the asset needs to be deleted and imported again ...

IMC incorrectly retains the state of a modifier set in a lower priority mapping context.

FJsonObjectConverter::ExportCallback_WriteISO8601Dates allows for writing FDateTime that does not have ticks

Context: `FJsonObjectConverter` is a built-in UE class that makes it easy to convert JSON objects to and from UStructs, including `FDateTime`, which implements a date and time. Problem: An uniniti ...

Inside the ViewportToolBar, the "Click to Expand" ComboButton works incorrectly with Display Scaling

When Display Scaling is applied (e.g., 125%) and the Level Viewport is resized, the ComboButton in the SViewportToolBar does not behave as expected. Normally, the ComboButton hides when there is in ...

Deadlock running anim modifiers that affect bone tracks on multiple sequences

Running anim modifiers that affect bone tracks can deadlock the editor when applied to multiple anim sequences. ...

GPU crash accessing Scene_GPUScene_GPUScenePrimitiveSceneData

GPU crash in DistanceFieldShadowing LoadDFObjectDataFromBuffer

GPU crash in LumenRadianceCache ClearProbeIndirectionCS

Incorrect derivative ops detection when Add node is used with Nanite Pass Switch node in material graph

Plugging an Add node which adds a constant value into a Nanite Pass switch node results in derivative ops to be detected where there should be none (which show up as red in the No Derivative Ops deb ...

When using Perforce, saving a level over another leaves the target umap file as "marked for delete"

When working on a level asset and using command "File – Save Current Level As..." to save it over a different level asset, the engine first deletes the target level (that's going to be overwritten) ...