The true fix is in another thread on this forum… it’s a damn replacement of the Registry file that takes you back to an unclaimed Server. I don’t know why manually removing the reg folders don’t do this but following this procedure fixed it so quickly, after I spent hours following a bunch of manual methods that never worked.
Here it is, the damn reg file replacement that allows you to clear the claim and then reclaim to make your new Library (or possibly salvage previous library)…