Permission issues are one of the few weaknesses that often appear in the Apple operating system and that is that nothing you do a little research with the terminal and file permissions, or rather experiment with, is easy to encounter permission issues.
Although I haven’t experienced any so far, I have seen more than one case of permission failure and unbootable Macs due to permissions associated with user accounts. Mac OS X has many permissions per account and an ACL listing associated with it .
If by any chance we have had a problem of this type but we have no idea how to solve it, we can turn to a tool integrated into the system that can help us in this regard. This tool can be found in the Utilities of the Snow Leopard installation DVD.
Once the installation DVD has been started, we have to go to the option “Change user password”. Inside this program we will find at the bottom the option “Reset permissions and ACLs of the user account”. Just by clicking this option we will have our user account with the permissions fixed.