Summary
UE 5.8: Movable lights with a Light Function remain counted as shadowed movable lights after Cast Shadows is disabled, and the viewport warning persists after the lights are deleted.
What Type of Bug are you experiencing?
Rendering (Graphics / Niagara)
Steps to Reproduce
- Place 10 native Point Lights in the level.
- Set all lights to Movable.
- Verify that enabling Cast Shadows produces the “Too many shadowed movable lights” viewport warning.
- Disable Cast Shadows on all lights and verify that the warning disappears.
- Assign the engine’s default Light Function Material to all Point Lights.
- Disable Cast Shadows on all lights again.
- Observe that the viewport warning no longer disappears.
- Delete all Point Lights from the level.
- Observe that the warning remains visible until the editor is restarted.
Expected Result
Lights with Cast Shadows disabled should no longer be counted by the “Too many shadowed movable lights” viewport warning, regardless of whether a Light Function is assigned.
Deleting all affected lights should immediately remove the warning without requiring an editor restart.
Observed Result
When a Light Function is assigned to movable Lights, disabling Cast Shadows no longer removes the “Too many shadowed movable lights” warning from viewport.
After deleting all affected lights from the level, the warning remains visible even though no matching light actors exist in the Outliner. The warning only disappears after restarting the editor.
Affects Versions
5.8
Platform(s)
Windows
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Additional Notes
Regression: The same reproduction behaves correctly in Unreal Engine 5.7 and older.
The issue reproduces using native Point Lights and the engine’s default Light Function material. No Blueprints, custom materials, plugins, or project-specific code are required.