Have been getting this message since before 12/28/18. Started documenting 12/28. Message happens on both Chrome and Edge. On 12/31 I decided to try another tab on the same Edge browser. When I logged in, the site showed my user id even though I couldn't logon at the 1st tab. I drew, but couldn't get to My Studio because of the 404 error. Tonight same thing, able to log in at the second tab, but not the first. Haven't yet tried to draw because wanted to get this post written. Even before the error message started, it took a long time to change screens on this site. Would get "waiting for response from..." Any help is welcome because I want to be able to draw here.
edited this post on January 3, 2019 7:35am.
Reason: Marking support issue as closed :)
I fixed a major lag error that had been building up on the "Your Studio" page, which is where logging in typically dumps out to. That might have been involved! I'm just puzzled because I'd expect a different error than 404 for a timeout.
Regardless, just glad it is happy and working for you now! :)