Error in template function VisibleSavedFilterNames

(imported topic written by SystemAdmin)

I am encountering an issue on one of our web report servers. After logging in and navigating to the Explore Data page, the following errors show up on the top of the page, with nothing else displayed on the page-

Error in template function VisibleSavedFilterNames:

Error in template function VisibleSavedFilterNames:

Error in template function HiddenSavedFilterNames:

This does not happen all the time, and I can not replicate the steps to produce the error. It just shows up every couple of weeks.

I can navigate to the Administration page > Errors and No errors show up to be cleared. The only way to clear the errors is to restart the service.

Any ideas where to begin investigation?