Right now when trying to modify the schema of a shapefile in use by multiple users, Pro returns a generic error telling you it's locked. This is helpful, but not everything. You need to use something other than Pro such as File Explorer to drill down to that particular layer's file location to see the lock files and determine who's using it. You might not know the file name or location of the file off the top of your head, so that's another step too -- to close the modal error and investigate your layer's properties before heading out on your search.
It would be really nice if Pro could just list these locks right there in the error box so I can see who's using it and ask them to close -- without the extra steps.