Are you entering
your center number correctly?
I'm having the same issue and submitted a ticket about it to support centre. My daughter's teacher suggested it might be due to her name having an accent in it. Ms. Pratt, does your child's name have an accent as well?
That's the same thing I keep getting too. Haven't been able to log on at all. The teacher is saying the accent in my daughter's name might be the problem, but she's not sure.