Key in use by myself

I have problem since yesterday, my key is used by me. Rebooting computer, internet, reinstalling diablo 2 didn’t solve the problem
Thanks for help

I’ve seen Blizzard reps say it could be up to a 24 hour wait. I’d say try not playing for a day or two, and if you continue getting the message 24 hours after the problem started, you should open a support ticket as well as posting in the Classic Games Support Forum.