Try adding this Extended Privilege to the user accounts in your solution file(s) [using the menu item: Manage>Accounts & Privileges>Extended Privileges]:
fmrestorelogin "FM Go auto-restore login"
Note: fmrestorelogin was replaced by fmauthenticate… in FMP 12
I tried that but I don't actually have FM server. I just use Filemaker Server Admin Console which my hosting company set me up with.
But surely you have access to your own files on that hosting service? This is a change to make in Manage | Security for your account's privilege set.