Hi,

As you can see the master password in the conf file which is encrypted, do one thing, add a ; in front of the master password.

Eg,

;admin_password = abcdefg

 As you add a semicolon, it will not get affect, now if you restart the service and check the UI, Odoo will ask you to set the master password.

Or you can edit and change the master password in the conf file.

See this: How to Recover/Change Master Password in Odoo

Thanks