I suddenly experienced this issue shortly after 12 PM (noon) EDT today. I did restart and also cleared all my network data, and tried a VPN, and nothing worked. No issues were noted at the time of submission of this comment on the MTG Arena status page, surprisingly, even though many Reddit users on the MagicArena subreddit reported issues with logins and availability of draft queues in the last two hours (starting approximately 11 AM EDT today).

Still unable to login despite reinstall and clearing data.

Come si risolve questo problema?

Cant login for a couple of days.

This happened to me today for the first time (right after the Aetherdrift Alchemy update)

I get the Unable to Login message on my desktop computer, but not on my phone or laptop. Have tried restarting the device, flushing the DNS, logging out and in again.

UPDATE: I found that by opening the client from the Start Menu instead of the Desktop icon meant that it installed an update and allowed me to login again.

I have the unable to login, authentication failed for UN: Timeout

Same issue here, unable to complete login after (I presume) the Aetherdrift update. Very disappointing.

Been in this situation for a week. Support is not helping. Has anyone ever been able to recover their account?

Unable to login for the last three days, any platform and on any network. Kinda ridiculous that it can go on for so long, please fix it!

Same here, unable to login after update

Same here

Tried PC restart, MTG reinstall, dns flush, winsock reset but nothing helped

Same here

Authentication failed for (Username)

After the lotr update today, I'm unable to login: Authentication failed for <username> Timeout issue. I was able to login to a dummy account. I was also able to login my friends account. Only my main account is unable to login to the server. Please fix ASAP.

Arena is absolute dogshit software and Wizards are ******* brain dead profit slaves. Absolutely useless company.

A few hours earlier was playing fine, after lunch, couldn't connect any more, i followed the troubleshooting and error continues, also on my mobile same error, already reboot my router.
Edit: i friend came and he can log with his account, after that, tryed again my my own acount and the "timeout"shows again

Experiencing the exact same issue.
I was playing a matchmade game, and in the moment I lost, I was disconnected and got this "Authentication failed ..." error.
What makes it more frustrating is the lack of acknowledgement from WoTC's side that this issue even exists.
I've uninstalled and re-installed a couple of times, performed a DNS flush and winsock reset, all to no avail.
Please fix ASAP

EDIT:
Works for me now, managed to log in on mobile (android).

I encountered this problem today. When I log in to the game, it shows "Authentic failed for username: Timeout". I tried many methods and still can't log in.

same error. tried everything that wizards of the coast suggested even flushing dns. nothing seems to work. tried logging in using windows/android/apple doesn't allow me to log in.. error: authentication failed.