Hi,
Please copy the J2ee_admin to administrator and check logging with that as in the logs it saying that cannot find administrator.
"I can't find the user "administrator" in the ume database in the portal page."
Please keep the password same as j2ee_admin. If this works this means that administrator was deleted from your system.
If possible please change the configtool parameters to administrator id.
Thanks
Rishi Abrol