Clearing cache sometimes clears it up. Sometimes it is persistent, but disappears later so just check back. You could also try different devices or open up an icognito tab and login from there to see if it works.
After trying a few ways and still getting stuck with same error, phone is worst where i hardly can even do any quest. I guess its my connection (playing in SG). Guess i shall stick to questing when playing in chrome.
Not sure if any of the mods still support this community, but they should be aware that the forums are infested with bots and that their forum needs to be upgraded.