Do sometimes assets just go buggy????

Been fighting with one of my assets and getting errors re: it’s UV maps. Things like ‘wrapping’ to lightmap overlaps. None of which seem to actually exist with the model.

Lost an hour trying to figure out wtf was wrong.

Then I create a new file - import the same asset - do a quick build. It’s perfect. Not an error.

What can we do to avoid such issues? I lost a ton of time on something that was entirely the project files issue.

If you set the resolution of the lightmap too small, the generated lightmap will have wrapping and/or overlapping UVs.

Did you create your second UV layout in a 3rd party software or in UE4?

As order66 said, just create a 2nd uv channel with a lightmap for every mesh, then you will avoid such problems