Telnet does not accept username !

Who can help.....
I tried to install the latest firmware on my 5big2 but telnet does not accept the given username!
See the attached picture. Can anyone tell me what is going wrong?
Regards, Jos
I tried to install the latest firmware on my 5big2 but telnet does not accept the given username!
See the attached picture. Can anyone tell me what is going wrong?
Regards, Jos