What are the most common reasons for not being able to edit UVs? In 2.80

I have unwrapped the UVs. But I can't edit them now. 
I tested this with another object in a different file and that was not a problem, so I guess it's something specific to my other file.
Also, the UVs only show while I have them all selected in the 3D view. Is there a way to have them all showing whether they're selected or not?

Thanks
Strangely, the solution was to remove the texture I had on that mesh.