Thank you very much for your suggestion but unforunetly it's not that easy. I've checked the username and psswd at least 20 times and in addition the username and psswd works fine on my opensource firewall.
Something the SRX is doing is forcing this error.
I've run the SRX on the back of the Hauwei in bridge mode and I recieve the same error. I think I might try the upgrade to 12.3 and see what happens. As soon as I have time.