The issue is most likely due to a broken Word addin. That said, repairing Word shouldn't require you to reactivate it.

Try starting Word in safe mode (i.e. hold down the Ctrl key while stating Word). If the problem goes away, a broken Word addin is the most likely cause. Restart Word then disable all addins, progressively restarting Word and re-enabling one addin at a time, then quitting Word until you find the culprit at the next re-start.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]