For the registry, I had the same issue today, related to [wlsdomain]/security/SerializedSystemIni.dat
In some cases, that file is corrupted, so you should try to restore it from a copy.
If there is no copy, try these steps: How to Recover SerializedSystemIni.dat File? (Doc ID 1602857.1)
My case was pretty simple, WLS had no access to that file cause somehow permissions were changed.
----rwxrwx 1 oracle oracle 64 Oct 4 16:09 SerializedSystemIni.dat
so solution was restoring the permissions:
chmod 640 SerializedSystemIni.dat
But how critical is this file for WLS ?
The SerializedSystemIni.dat file contains the hashes for the passwords. It is associated with a specific WebLogic domain so it cannot be moved from domain to domain.
If the SerializedSystemIni.dat file is destroyed or corrupted, you must reconfigure the WebLogic domain. Therefore, you should take the following precautions:
* Make a backup copy of the SerializedSystemIni.dat file and put it in a safe location.
* Set permissions on the SerializedSystemIni.dat file such that the system administrator of a WebLogic Server deployment has write and read privileges and no other users have any privileges.