This just happen to me last night, i cannot enter the dashboard, eventhough password are correct.
Nothing changed. no additional software installed.
These symptoms also happen to fpkmgr login which i set using login password.
But the weird things is, transmission web (port 9091) though also set using password, can be reached.
and also twonky web (port 9000) is accesible.
I’m using the latest firmware (the last before 06/26 update)
good thing I enabled SSH. if there’s a comprehensive tutorial in using dashboard functionality with SSH, i no longer need the dashboard. but right now, I still need the dashboard to manage users and shares.