PC here, keep getting the 201 login error since the update. Also notice the game is not/cannot retrieve announcements. I have verified and repaired the game files, all appropriate exceptions are in the firewall, yet still can't login.
Still having the issue. Best I can assume, from looking at older threads, is the dev's have offered no support or fix. One suggestion is to do a clean install but for me that's not really a practical option seeing as it'll take me half a day to dl the game again and I really don't want to have to do that every time there is a patch.
Fixed the problem for myself. In my case, I use ESET antivirus, for whatever stupid reason my antivirus' GAMER MODE was not allowing ESO through my firewall, a simple exception would not work so I simply disabled gamer mode.