system extension cannot be used AppleUSBEthernetHost.kext

Just tried your solution, Trane. Glad it worked for you but unfortunately the installer threw the same error message again for me. Aside from the message it seems to have completed normally and I can use iTunes as normal. Haven't got iPhone with me to test connecting that.

Have sent feedback to Apple so they're at least aware it's happening. Based on number of people reporting this error, it surely must be a problem with iTunes 11.4. I don't have the expertise (or the skills, frankly) to explore more deeply myself. I'll wait for Apple to ride to the rescue with a fix/new point release.

Trane,

All 3 symbolic links were bad. There were 4 Code* files, now there is just the 1 (CodeResources).

You should have removed the CoreDirectory symbolic link as well.

Trane,

"Restoring the extension to an earlier version and rerunning the new iTunes installer ALSO results in load errors, BUT, the contents of the extension itself are now a mix of old and new."

You don't want that 🙂 You don't want the old and the new mixed.

I trashed the old kext and downloaded iTunes 11.4 and installed it from the downloaded .dmg - it did not create any symbolic links in the newly-created kext, and I did not get any pop-up error message about the new kext like I had previously when done via Software Update.

To make a long story short:

Trash the 11.4-installed kext, and either reinstall iTunes from the downloaded .dmg version or else roll back to the (entire) old/previous version of the kext.

AppleUSBEthernetHost.kext error on installing iTunes update

This has the same link for removing the .kext and re-installing iTunes 11.4.

Greg Earle wrote:

Trane,

"Restoring the extension to an earlier version and rerunning the new iTunes installer ALSO results in load errors, BUT, the contents of the extension itself are now a mix of old and new."

You don't want that 🙂 You don't want the old and the new mixed.

I trashed the old kext and downloaded iTunes 11.4 and installed it from the downloaded .dmg - it did not create any symbolic links in the newly-created kext, and I did not get any pop-up error message about the new kext like I had previously when done via Software Update.

To make a long story short:

Trash the 11.4-installed kext, and either reinstall iTunes from the downloaded .dmg version or else roll back to the (entire) old/previous version of the kext.

Alas, doing that results in attempting to load the kernel extension throwing errors. It's clear that the installer from the download DMG versus the Software Update DMG are behaving differently (one throws the extension error, the other does not), but either installer leaves my system with an unloadable kernel extension. That is true whether updating the kernel extension from the iTunes 11.3 version or replacing the deleted extension outright.

This error message appeared after five minutes when I just install iTunes 11.4 on Snow Leopard, version 10.6.8...

Below, the error screenshot (It's a Brazilian Snow Leopard 10.6.8 version...):

Any ideas how to fix this error ?

Thanks !!!

You are running 10.6.8, most posters reporting problems are running Mavericks.

Hi, Loner T ! Thanks for your response... Yes, I running on Snow Leopard, version 10.6.8... I just finished the Itunes installation and I got this error message too. But I afraid this error could cause anotherissues on the operational system or on Macbook... In this time, the system looks normal...

Just adding that I have the same problem. Running Mavericks on 27" iMac. I've searched the web and read many forums about this problem. Some people seem to think they fix it because they don't get the repeat extension warning after a "fix" and re-download of iTunes. In most cases I've seen off a number of different forums someone duplicates the said fix (with the same hardware) and they get the error again. So, I can't believe there is a true and tested fix at this point out there, not to mention Apple refuses to address the issue with so many peeps in distress over it.

How can you address issues on an Apple forum , of this magnitude, and no one from Apple gives a **** enough to say anything? I'm lead to believe that we have to fix it ourselves, follow what others say worked for them. I don't know about going into the Terminal, deleting & typing code into it, but I guess if I don't I'll suffer consequences later if not sooner?

Thanks Apple for the direction, no advise from you. Have to go it alone, real nice, gee which "fix" of the dozen I've read about should I try 1st? Any hints, no- you wouldn't want to ruin the party! Well, I don't know what Terminal is but I know how to get there, that seems to be where the action is, no choice but to do as the others do cause no help from mother....

P.S. I'm under Apple Care so when I totally screw it up I'll just send it back, then you can fix it "hands on"

I am also having the same problem with the error message. I am running Snow Leopard 10.6.8. I also am not able to sync my iPhone 5. Now the SYNC Buttom is grayed out when I connect my iPhone with the USB cable. It will also not sync via WiFi. Is there a fix on the way or do we have to do something else?

^I don’t understand these last two posts. *Scratches head*

Either remove /System/Library/Extensions/AppleUSBEthernetHost.kext and re-install iTunes 11.4 from the downloaded .dmg version, or else remove it and replace it with the previous version of the same kext, like from a Time Machine backup.

Reboot the system afterwards. (Smarter people can just try reloading the kext and not reboot, but a restart will also do that for you.)

Either method should work. Theoretically, at least 🙂

(When I get home from work I will try to sync my 3 iDevices to verify. At home I am on 10.6.8. I got the error when I used Software Update, and used the “Trash the old kext, download the iTunes 11.4 .dmg from the Apple downloads site, re-install iTunes from it” method. No popup error.)

I'm running Snow Leopard 10.6.8 and when I did the 11.4 iTunes update, I got the same system/Library/Extensions/AppleUSBEthernetHost.kext error. My iTunes no longer sees my iPhone or my iPad.

I thank all those who are trying to give answers for a fix, but I'm hesitant to do a theoretical fix and start monkeying around with system files when I don't know the ramifications. Apple needs to get a fix put up for this ASAP. It seems to be pretty widespread.

Although I'm using Snow Leopard, I'm pretty sure variations of this approach can be used on Lion, Mountain Lion and Maverick.
I believe I found (one) way to fix this error...well, at least it worked for me (see below):

There seem to be various threads addressing this issue and no "one" way is the right way for everyone. I'm running my Macbook on OS X 10.6.8 (Snow Leopard). Once I installed the iTunes update, two things happened: my iPhone became corrupted when I sync'd via USB and then my iTunes stopped recognizing the iPhone as a "sync-able" device -- meaning it would show up on iTunes but when you went to click sync, the sync button was unavailable.

I tried locating the .kext file, deleting it, repairing it, replacing with an older version, entered different commands in terminal but I kept getting the same error. Ultimately, I fixed the problem fairly simply, but it may not be something everyone is willing to do. If you have an external hard-drive and had your computer hooked up to Time Machine, this is what you should do:

1. Hopefully you'd been backing your computer up automatically fairly recently, and you have some this stored on an external hard drive via Time Machine from before iTunes 11.4 was downloaded onto your computer.
2. If you haven't done so already, and your iTunes library isn't corrupt, Backup your entire iTunes library to an external hard-drive (if you don't care about your library, ignore this step...this procedure might not work, however, if your first backup of your iTunes library is via version 11.4. If you go through all of these steps and you encounter the same problem, restore your itunes to an older version via Time Machine, then redo steps)
   • To do this, create a new Folder on your hard drive and call it "iTunes"
   • Go into your iTunes preferences > Advanced > under "iTunes Media folder location" we want it to say /Volumes/(Your Hard Drive Name)/iTunes

     Next to the "iTunes Media folder location" dialogue box, it should read CHANGE or RESET. Click CHANGE, navigate to your external hard drive and locate the newly created iTunes folder...your computer should automatically start to transfer your library to the new destination.

3. Backup and "new files" on your computer that you create since updating your iTunes to version 11.4 (i.e. new iCal entries, documents)
4. Backup your important files (I have mine in dropbox but chose to be safe and backed them up on an external hard drive as well)
5. Once you have everything saved, you're going to want to go through the process of completely restoring your entire computer (essentially wiping it clean).
   • To do this on Snow Leopard, you need to have the Mac OS X Snow Leopard Installing disc.
     1. Insert disc > when the Install screen pops up, select Utilities... > it will then prompt you to Restart your computer
     2. After your computer restarts, it will prompt you to reinstall Snow Leopard or select a different option from Utilities which can now be found at the top of your screen on the toolbar. From there, select the option that is along the lines of Restore from Backup Using Time Machine and then select which backup you want to restore your computer to ... since iTunes 11.4 went live on Sept. 10th, I would restore to any date before that.
     3. When your computer restores itself to your chosen backup, your computer should be exactly as it was on that date, iTunes included. It's as if nothing ever happened.
   • To do this on any later OS X, I believe you have to restart your computer and then hold COMMAND+R before the grey screen appears. From here, I believe it will prompt you similarly to the Snow Leopard procedures 1-3 as listed just above this bullet point.
6. When your computer prompts you to update iTunes to version 11.4 from whatever version you reverted back to, DO NOT UPDATE. Keep your old iTunes version and wait for this thing to be addressed by Apple.

This procedure worked for me and although it's a bit tedious, it fixed both my iTunes and iPhone errors. Note: I did have to erase and restore my iPhone through an old backup via iTunes once iTunes was working again. Try it out. See if it works for you. MAKE SURE YOU BACKUP YOUR FILES BEFORE ATTEMPTING ANY FULL SYSTEM RESTORE.

Think I may suffer this error message as it seems very very wide spread and starting to happen after the latest iTunes update, last time I messed with a kext file after getting this sort of message I ended up a non booting drive (

Also I cannot download the latest iTunes from the Apple website, it just does not download.

So I am waiting for Apple to move on this.