Check for outdated addons if you have them, repair the game via the launcher, mess with your gpu driver if you recently updated it, and if nothing works just reinstall as a last resort.
Click on storage on the left then scan next to the deep clean, and clear the DirectX shader cache. Also check under the other application items option and see if there are old log files or other things under elder scrolls online.
You can try checking the Reliability Monitor if you're on Windows. Just type "reliability" in the Start Menu, and look for events around the time ESO crashed.
The OP isn't the only one with this issue. So far I've:
- Checked all add-ons are up to date
- Repaired game (4x)
- Restarted modem and router
- Restarted PC
- Checked AV permissions (even though there's been no problems for years)
- Check Video drivers (up to date)
- No events in Event Viewer
- Reliability shows ESO App crash with ESO64
- Problem started when I logged in last night after work. Prior to that everything was just fine.