Atm10 curseforge stuck at verifying user

Came home ready to play some ATM and curseforge is stuck in a loop of "verifying user" before saying your login session has expired, when I try to login, it verifies fine, but then gets stuck again at 5 percent, verifying user.

I left the PC logged in when I went to bed last night, and have been advised there were a couple of power cuts today.

Any ideas?