Static Mesh LODs cannot be removed after import from the Static Mesh Editor unless you have Simplygon installed. Hovering over the tooltip for "Number of LODs" indicates this as well with "Auto mesh reduction is unavailable! Please provide mesh reduction interface such as Simplygon to use this feature or manually import LOD levels."

As an example, If I import a single mesh and then manually import a LOD using the "LOD Import" drop-down and select "Import LOD Level [X]", I will never be able to remove that LOD without reimporting the base LOD to wipe any existing LODs that were manually imported because the slider is grayed out.

Steps to Reproduce

-Ensure that Simplygon has not been configured for the editor
-Add a LOD to a static mesh (easiest to just export a static mesh with only one LOD, and then reimport it as LOD1)
-Attempt to remove LOD1 from the static mesh

Expected result: LOD can be removed

Observed: Impossible to remove LOD.

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Affects Versions4.
Target Fix4.15
Fix Commit3170524
Main Commit3229477
CreatedJan 18, 2016
ResolvedOct 21, 2016
UpdatedApr 28, 2020