I had this problem starting late last week. Previous times I saw the issue have usually been due to the server being down, and fixed simply by waiting less than a day. This time was different, and I and an acquaintance tried half a dozen devices over 5 days. Those with Windows 10 failed every time, including after trying every troubleshooting option suggested by Wizards Support. All devices with other OS were fine.
Our eventual solution: use prior version of the Arena launcher, which can be found in older versions of the installer (we used one from 2020 that had been saved way back then). We ended up downloading a 5GB update, and it had a few other issues, but it played perfectly.
I had this problem starting late last week. Previous times I saw the issue have usually been due to the server being down, and fixed simply by waiting less than a day. This time was different, and I and an acquaintance tried half a dozen devices over 5 days. Those with Windows 10 failed every time, including after trying every troubleshooting option suggested by Wizards Support. All devices with other OS were fine.
Our eventual solution: use prior version of the Arena launcher, which can be found in older versions of the installer (we used one from 2020 that had been saved way back then). We ended up downloading a 5GB update, and it had a few other issues, but it played perfectly.