"Maximum session limit reached"

So I had been playing Atwar today, and after refreshing the game page, I get this notification popup on the screen that says "maximum session limit reached (4) - Reload?" I clicked "ok" several times, but each time it reloads the same popup appears. I had no other tabs or windows open at the time. I closed and restarted my browser, and the same problem still occurred afterward. I tried logging out of my account, restarting my computer, and using a different browser. None of that has worked either. Can somebody please tell me how to fix this problem, because it makes it impossible to get to the game lobby. Below is a the link to a screenshot of the popup that many of you guys are probably already familiar with:
https://prnt.sc/ggmkur
Thanks,
-Marco_Rubio