Over 800 objects have one UV map called “UVMap”. Visible in the Object Data Properties under “UV Maps”.

I now want to add one new UV map to all these 800 objects. What I tried and what I found via Google sounds logical, but it doesn’t work in Blender 5.0.0. Maybe a bug?

When you select multiple objects and then click on the + at the side of the UV Maps list, a “UVMap.001” appears. But it just gets added to one of the objects, not all of them. Even if you alt-click the + sign.

According to Google search results, this should have worked.

The next step would be to make UVMap.001 the active one for all selected objects.

Update: I gave up and used a script.