UPDATE: We will be re-implementing the search pop-up function this afternoon starting at 3:00pm. It will be pushed out to the main uwaterloo.ca site first, and will be gradually pushed out to all other WCMS sites afterwards. It may take a couple of hours before all sites have the pop-up search restored.
A third-party script was causing issues with the pop-up search; this issue has now been resolved. If you are still seeing the error message, you may need to clear your browser cache.