Having the same problem with 3.0.1 as others, where I will login and it states:
Unable to log in. Please restart your computer and try again. If the problem persists, please contact support.
Release: 3.0.1, Win 10 Home.
No vpns. No funny business. No CCleaner. No corrupt files.
Ran dism, SFC Scannow, etc. everything's solid. Restarted 5 times, redoing steps from other threads. Nothing.
Had attempted a fresh install on my old rig (now my music machine).
Items were installing fine this morning when I was able to login, then got stuck on a pack for a few hours and when the app restarted, bam.