I'm also getting the Error 102 when opening the launcher and trying to patch. Clicking "Repair" also gives the same error. I've tried all the official troubleshoot steps without any success.
I've seen some have bypassed the error by using a VPN. I'm reluctant to trying this, as it's not a permanent solution. This issue happened today after the maintenance. The fault doesn't seem to be on the user end as far as I can tell.
I'm wondering if ZOS are aware and working on fixing this, or if there is any other way you can help me (and others with the same issue) to successfully patch the game and log in?
Thank you.