Error 308 usually occurs due to inactivity. If you are away from the keyboard for a certain amount of time, the server will disconnect you automatically. This may also happen during particularly long loading times when the server is busy or if you haven't touched your keyboard or mouse in a while.
If you get this error, you should exit the game, check your network connection, and try again.
If the issue persists, you should ensure that your machine meets the game's minimum requirements.
If you do meet the game's requirements, you can try lowering your video settings (such as resolution) from the main menu and try again..
The Elder Scrolls Online: Tamriel Unlimited - ZeniMax Online Studios
I solved the issue by going into settings and repairing the files. I turned AV software as well. Previously, I just clicked on the repair button where I would normally see the PLAY button. So, maybe just clicking on that didn't repair enough files.
P.S. I also updated my ticket to reflect I solved the issue as well.