Hello   @billsfan2555555 

Thank you reaching out to us.

The local login password is reated by user when we first time login the range extender's web/ or login RE on tether APP. 

Can I know do you try to login using 1)  local login password: requires password or username & password 2) tp-link ID login: requires tp-link id email account & password of tp-link ID (this happens after range extender has bound to tp-link ID) 

If a login password is incorrect , you could factory reset  RE and create a new login password for it. Then reinstall the range extender. 
RESET: With the extender powered on, use a pin to press the RESET button until most LEDs flash once.