I don't see any obvious suspects among your extensions, but any ad blocker could be the source of
. The ADBlock and WIPR (I presume that is WIPR Part 1, WIPR Part 2, & WIPR Part 3) extensions duplicate one another functionally, so you might try deactivating one or the other, you don't have to delete them, and see if that error re-occurs. But neither of those should effect your tab settings.
Tab settings are stored in a preference file somewhere in your user Library which leads me to suspect some app outside of Safari as the culprit, but at the moment, I have no clue what it would be.
