All day, today, I have been getting this error message. It comes up when I first open the app and also every time that I click on my profile picture to see my Class and Rank:
"Uh-oh! Please try again or if this issue persists contact SMG Studio support. Error 904"
It has my rank at 8,195 and listed as a "Beginner" (should be at least "Intermediate" with that ranking) and my rank has not changed, at all, after my last few games.