We have an Excel-add that has been added via Tools|Add-ins and works.

However, when you go back to Tools|Add-ins you get the message

"Cannot find addin c:\xxxxx. Delete from list?"

If we answer No, add-in continues and we can verify that the XLA does exist.

If we exit Excel and re-start, Excel does not complain about the XLA being
missing, i.e. the registry OPENn is set correctly.

Any ideas why Excel is displaying this message even though the Add-in
filename and path is valid...