I am trying to use Xrefs to insert a key into a current set of drawings but when I go into the Xref manager, which shows that there are no Xrefs currently attached, and then proceeding to Xref in the key, it gives me an error that says the current drawing is invalid because it is already contains the Xref. The drawings did use to have an Xreffed table, but they were properly detached, and I have no idea why it stills says they are there because the manager says it isn't as well as it's not visual on the drawing. Any help would be greatly appreciated.
Does it have any xrefs attached?
Run an audit on the drawing and fix errors. Try again.
Purge the drawing and try again.
As a test you could wblock all of the relevant data out to a new drawing and try xref key in from there.