My IP address is drastically different from the one I created my account with, however I'm able to login just fine, most times.
When I do, however, encounter this error, closing FH and re-opening it usually does the trick. Sometimes I need to do this up to 3 times, but I always manage to login eventually.
Questions & Answers (Q&A)
Will the login tab stay forever or will we be able to login normally again sometime?
As of now, this tab is here to stay. We understand it might not be optimal for some users and might cause some hassle, but it's for the better.
Will I be able to sign in to multiple accounts at once?
You are able to sign into several accounts at once, however you might need to use different browsers to connect to more than one account at once. Download Firefox, Chrome, Opera or any other browser of your choice and run it in tandem.
It will not let me connect to the game, why?
If you're experiencing issues it could be how your browser is currently set up. We do not allow any proxies so please disable any proxy settings you might have enabled. Also do not run the browser in incognito/private browsing mode and have cookies enabled. If you still have issues feel free to try another web browser all together. Also do keep in mind that we do not let any banned users connect to the game
I hope this may answer some of your questions.
There's also the other thing where if you haven't logged in for a really long time, your account may not be in records anymore.
But I doubt this is the situation.
Like everyone else said:
1.) Check your WIFI.
2.) Use the "Play Game" button.