REceiving error - system extension missing / cannot be used

Question

Hello,
Posting here because I see this error frequently when doing updates. I received and performed a system update for iTunes yesterday and received the following twice:
System extension cannot be used
The system extension "/System/Library/Extensions/CNQL3202_ClassicNotSeize.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update.
I see these frequently when performing updates so I suspect it's not iTunes specific. What is the missing file and where can I find it / what can I do to eliminate the error?
Thanks much in advance.
E.

Answer 1

It sounds like you made a permissions change that you extended to the entire drive, thus making all extensions unusable.
Start by doing the following:
Repair the Hard Drive and Permissions
Boot from your OS X Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities menu. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer. Now restart normally.
If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.
This will most likely take considerable time because DU will need to fix permissions on every system file affected and there are tens of thousands of files. Perhaps with any luck this will fix the problem although no guarantees. I hope you have a backup of the previous system before you made the permissions changes.