We might need some more informtion about your problem but my first suggestion is to see if the Xref has more than one copy of itself in the drawing. I usually Xref in legends, Titleblocks etc. and if I have to remove an xref, I first have to delete all but one copy of the XRef.
You can do this easily by using Qselect to select all XRefs and compare the number of items selected to what you have listed in the Xref dialog.
Jason's suggestion is very good. However, in case the issue persists, please check the drawings for corruption (using Recover and Audit), or upload the drawings so that we can have a look.
If you don't want to upload them here, let me know and I'll create an FTP folder for you (and check the drawings in privacy).
Product Support Specialist
In AutoCAD 2012 I have an xref (Xref A)that appears in the External References window, I can't detach the Xref A for the command line reads "Xref has multiple references. Not detached." yet when I detach all the other xrefs in the file leaving the opened drawing and only Xref A available. I select QSELECT and the External Reference is not an option in the pulldown menu under Option Type. Nothing on the model space screen is left to select (for a List properties) and I am at a loss of what to do.
1) I revised and renamed the original Xref A dwg. and the "Saved Path" is no longer viable leaving the file path text in the drawing.
2) There are multiple paper space sheets (12) in this drawing file.
Xref A is not needed or used and everytime you open the drawing and the "Unresolved Reference Files" pop up gives people in the office that something is wrong. I do not want to 'reconstruct' the drawing from scratch because we have multiple people that utilize our drawings and xrefs.
Why can I not Detach this Xref A?
After you detach the other XREFs, open the main drawing and use ETRANSMIT.
Does it add any XREFs?
If you upload the resulting ZIP file then we can have a look.