I received an email saying I was invited to the beta, but I couldn’t access Muse.
PS. hard refresh and log-out + in have already been tried 
Hi @heavyobject - in our authentication system it seems like you have yet to be invited to Muse Chat, not to be confused with Muse Tools (sprite + texture). Really glad you are so eager to get started using Muse Chat, so stay tuned and keep an eye on your email!
Best, Martina