security.xml file is corrupted

If security.xml file is corrupted how will restore it?
First, what is file corruption?
Corrupted files are files that suddenly become inoperable or unusable. There are several reasons why a file may become corrupted. In some cases, it is possible to recover and fix the corrupted file, while at other times it may be necessary to delete the file and replace it with an earlier saved version.

What are the chances of security.xml becoming corrupted? There are chances for any config file to become corrupted.

Things to understand:-
1. How to avoid this?
2. What to do when this happens?

1. How to avoid this?
When you plan to edit Security.xml or any configuration file, better to take a hard copy back up or run backupConfig script. Hard copy backup, cp file as security_bak.xml, then make make changes to security.

2. What to do when this happens?
Say, on 5th, Tuesday, Feb you made changes to your security, it got fat fingured or corrupted, goto your system admin, revert it back to last working copy.
I would do like this. I would talk to my system admin and ask him to load security.xml from lastnights backup. We at our office, have nightly backups and weekly backups. We retain a months historical backups.

OR - If you know your security model completely, you can manually goto security.xml file, set security to false. save and recycle your server. It sets secutiy to false means no security. Now, set your security again.

Again, When will you modify security.xml? This is not an every day task. You will edit your security at the time of setting up new installation, or when you have a change in LDAP info or, when there is a need to add a new user or group etc. So, its always a good practice to take security.xml backup before you modify it.

There is even a better way to do this, specially in Production Environments. Let your versioning system take care of it. Meaning, check in your configuration into a version control system. If you make any change, it can be tracked.