PFF2 Form

Hello,
Im starting my first year of university in September. Iv'e applied for student finance and put in the correct details of my dad and my step mum, which was asked for. They have both received the email to support my application. However, when they log into student finance, they are told they cannot continue any further and are told to upload a PFF2 form.
I don't understand why this has happened considering I put in their correct details? They have both supported applications previously for my sister who attended university. The only difference from the last time they supported an application is that my step mum and dad have gotten married, therefore her surname has changed to my name, whereas before she had a different surname.
Can someone tell me why this has happened, and should it take very long to process the application when they complete it?
Thanks.