Hate to bump a semi-old thread, but I appear to be having the same exact issue. I've also tried to reset my password, but every time I try to, it shows me a page with "Bad Reset Code" on a black background--no matter how many times I send a password reset request, it shows the same message.
Alternate accounts do not work, nor does changing FH clients, disabling my firewall entirely, manually allowing FH access through my firewall, or using a mobile hotspot to connect. I don't have a spare computer, so I cannot try that, but from other threads I've read it doesn't work anyways. Logging in with the same password works just fine on the "play game" tab and on the forum, as you can see.
Additionally, it's worth noting that even though I've tried to log in more than 5 times, I haven't gotten the 15 minute ban from too many incorrect password attempts. This makes me think that it isn't the password itself, but something wrong with the client or FH itself.
Please keep us updated on what the situation is, and if any fixes have been found!