ex6120 won't accept router password

[Dddunny]

please help,

my password is correct on my router, i have double checked it by deleting and rejoining. I put extender back to factory settings but it wont accept my password.

please help i am losing it here

[plemans]

did you set it up via wps? 

If so, factory reset it and re-install it using the installation wizard and not using wps.