Resetting Excel Add-In (xludf error)

Periodically Microsoft Excel’s cached version of various add-ins become corrupted and stop working as expected or at all. The most common indicator this has occurred is that singlepane add-in formulas will appear with xludf_ in front of them and will not refresh.

If this occurs, follow the procedure below (Exactly) to reload the add-in:

1. Go to File menu in excel
2. Click options in bottom left
3. Select the Trust Center tab
4. Click the Trust Center Settings button
5. Go to Trusted Add-In Catalogs
6. Check the box that says “Next time office starts, clear all previously-started web add-ins cache.”
7. Click OK, OK again to close settings.
8. Exit out of ALL Office applications (word, outlook, powerpoint and excel).
9. Reopen Excel and open the add-in.
10. The add-in should load and you’ll have to login again.