If you are having issues logging in, like me....
I was able to fix it by installing and turning on a VPN on this laptop.
Since yesterday, I couldn't log in AT ALL using Plarium Play. I could log in from my phone though. Using my phone isn't a good option since it turns into a burning handful of lava when running Raid. Installing Windscribe on this PC let me log back in. I didn't change anything else, didn't clear cache, didn't reinstall.
Community Managers are aware of this problem, but until it is totally fixed, this is the workaround that worked for me at least.
Windscribe is free for up to 10gbs per month if you need a VPN option to get you through to Monday, when the full Plarium team is back in the office. https://windscribe.com/