Re: Unable to add a model device by serial number (But Success when using Discover and PSK
Just found the answer.
By default, FMG will use username admin and empty password to build up the FGFM tunnel. But if you login to FGT to add basic config, you are forced to change the default (empty) password. To method to solve the issue：
1. Use USB to load basic config.
2. Create another super user on FGT and delete the password of user 'admin'.