"System extension cannot be used" after installing iTunes 11.4

Installing latest version of iTunes (11.4) today led to the following error message:

System extension cannot be used

The system extension “//System/Library/Extensions/AppleUSBEthernetHost.kext” was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update.

I'm able to use my USB drive for Time Machine, and that appears to be functioning ok. Why this error message? Anyone else had it? And what does it mean for the continued safe operation of my MacBook? Would be reassuring to know if this is happening for anybody else, and if anyone else has found it affecting them. (Other than the distraction of getting a worrying error message that I take time out to report?)

Thanks in advance.

MacBook Pro, OS X Mavericks (10.9.4)

Posted on Sep 10, 2014 6:02 AM

38 replies

Sep 18, 2014 4:50 PM in response to Coola Boola

Thank you all for the fix. I deleted the problem file line and reinstalled the new iTunes. Everything works fine now.

Sep 19, 2014 2:14 PM in response to Coola Boola

I think this problem has been fixed by Apple, I had to restore my system to before the iTunes 11.4 update was made available (unrelated issue) anyway when the update popped up in the app store again I let it sit there for a few days. Today I noticed it disappeared for several hours, then reappeared bundled together with an OS X update 10.9.5. My guess Apple fixed the AppleUsbethernethost.kext problem.

Sep 22, 2014 10:33 AM in response to Amazin' Mac Mini

On my 10.7 Mac, where I had installed the original ITunes 11.4… the update installed on 9/19 didn't appear to fix anything.

On my 10.8 Mac, where I had not installed the original ITunes11.4… waiting and installing it the first time with the update on 9/19 didn't cause the USB kext problem

Sep 22, 2014 12:47 PM in response to fausttiger

Posted a possible solution here: How I solved my "not-syncing since upgrading iTunes" issue

florita1

Level 1

4 points

Oct 23, 2014 3:56 AM in response to nilsson58

Thanks - that worked for me. I'm up and running again.

Robleo59

Level 1

0 points

Jan 13, 2015 8:24 PM in response to Coola Boola

I run a 10.6.8 leopard os. I remove the file AppleUSBEthernetHost.kext.

I had to remove Itunes and reinstall an earlier version 10.6.3, then had use apples bug fix called MacOSXUpdCombo10.6.8 for it. and also had to install java new version too. everything works. thank god . it took all day but its done.

Robleo59

Level 1

0 points

Jan 14, 2015 6:47 AM in response to Robleo59

Also, I unchecked updates so new versions of software wont upload,If it works why fix it, If you purchase new software make sure its compatible with your OS system. I had to reload my printer drivers as well. The new yosemite OS wont work on my 2007 macpro intel quad duo. I have 4 gig of memory and 1 tb hard drive. The only problem I ever had was a hard drive crashing and since I didnt have the os system disk I had to purchase the leopard os. But since I fixed the Appleusbethernethost.kext file. my 10 usb port hub works better, I mean now my android shows up and my card reader. Go figure

Mac Pro

Jan 14, 2015 11:55 AM in response to Robleo59

I kinda miss Leopard. Things could be fixed.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

"System extension cannot be used" after installing iTunes 11.4