Bbylls,
IF the file reference is related to NX it can using Excel "File, Options, Add-Ins"
If there is an entry in the list of add-ins labled "UG", highlight the row and look at the details to see installation location looks correct (or is it for an NX version other than NX 8.5?)
Then set the "Manage:" option menu to "Excel Add-Ins and press the "Go..." button,
uncheck the box for UG, "OK".
Then restart NX.
HTH,
Joe