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)
Had this problem just a bit ago, searched it and what fixed for me is either add an exception to your antivirus while repairing the client, or disable it while repairing. I just added the exception and was able to log in.
i have allowed it on the fire wall but it still wont work i have mircosoft security and it should be allowed allready but still not working. it run the repair like 4 times now