Maintenance for the week of March 25:
• [COMPLETE] ESO Store and Account System for maintenance – March 28, 9:00AM EDT (13:00 UTC) - 12:00PM EDT (16:00 UTC)
I know sometimes that issue pops up with some grouping addons. Try deactivating your group addons to narrow down which it is, and then you can ask on the addon creator's page.