My employee accepted the invitation to WorkForce and could log in but kept getting the message  "We weren't able to show your payroll info."  After wasting way too much time on it, I simply asked my employee to give me a different email address.  I sent the invitation to her new address, she accepted and was able to see all her paystubs without a problem.  I don't know, but am guessing she had previously used the original email address for some other Intuit product (maybe Turbotax?) and that was causing the issue.