Hi,
System is having the issue because you deleted the J2ee_guest.
Where is the ume of this portal. If it is BW backend system then just create the j2ee_guest user in the ume client.
Check the below two notes.
1883674 - The AS Java cannot start due to USER_AUTH_FAILED exception
1707693 - J2EE engine startup fails due to backend user account not in validity date error
Thanks
Rishi abrol