firmware upgrade ex2700 cannot login to mywifiext.net

When I upgraded the firmware of the range extender EX2700, it asked me for email and password. When I try to log in to mywifiext.net providing same email and password it shows error invalid username.

my email is quite long in this format :  xxxxxxx.yyyyyyy.zzzzzzzz@domain.com  I am not sure if because its lenght there is any problem.

the old admin / password  doesn't work anymore.

Thanks