I managed to get it sorted here by rebooting my router. Seems that a change of IP address did the trick ( UK IP addresses are generally dynamic and change each reboot)
This has happened to me a few times as well. Restarting the router always works. On a side note, while I have this error code, the main Elder Scrolls Online page does not display correctly.
After recent patch, I had same problems, several times I tried repairing with no avail, also had main page display problems. Uninstalled game and launcher, Reinstalled game launcher, restarted router, now is reinstalling game(which wouldn't do before I restarted router) and is a waiting game till tomorrow when hopefully all is well and I can continue playing.