Invoice - user invited unable to access

Invoice - user invited unable to access

Hi, I have invited an user to Invoice, make active, is showing the "Invited" label.

The user has received the email, but when trying to access invoices, a message of Administrator has you marked as Inactive is coming, so the user is unable to access. I have double check and the user is active but waiting as Invited...
We have Standard version, so can have up to 3 users...

I would appreciate your help...