system extension cannot be used AppleUSBEthernetHost.kext

Problem experienced and solved using erase “//System/Library/Extensions/AppleUSBEthernetHost.kext” and reinstall iTunes 11.4 DMG on OSX 10.6.8

I am concerned about updating to iOS 8.0 on my iPad until apple resolves this issue! I wonder how many users have been shut off from backing up their i-devices and don't even realize it. At first I thought the backup was just taking a little longer than before. No backup errors messages were noted!

I'm running Snow Leopard on a 2009 imac. Software update has been bugging me for months to do the itunes update. Even though everything was working fine I finally decided to do it. i got the same error message as everyone else so now I'm sorry. I'm nervous about deleting files and trying to fix it myself. I hope apple does something. I'm afraid that because they don't support Snow Leopard, that I might be out of luck, but that doesn't seem fair. I'm crossing my fingers and hoping for the best.

Ryan, for what it's worth, I'm also running Snow Leopard (10.6.8) on a 2009 MacBook and Tingly's fix worked great for me. Here it is:

I fixed it by opening up a Finder browser where I found AppleUSBEthernetHost.kext and dragged it into the trash can. Then, I downloaded and installed itunes from https://www.apple.com/itunes/download

I have my printer plugged into my USB and I'm unable to print. So frustrating!

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

I had the same issue (using 10.6.8). I found that weird extension and dragged it to the trash. I downloaded an installed the drivers for my Epson printer, fresh. I restarted the computer, and the printer worked. I even dragged the extension back to where it was, and the printer is fine.

I don't know why that worked, but I'm SO thankful it did.

Confirming the fix shared and tested by many in this discussion WORKS:
- trash the kext file giving the error
- download iTunes from apple.com and install it (don't worry - it will install fine over the existing one and it won't delete any of your iTunes content)

- restart the Mac

Issue that I had:

- my tethering via my iPhone 5S (via USB-cable) suddenly stopped working; when I rebooted (haven't done it for long time), I got the AppleUSBEthernetHost.kext popup error

Issue I did *not* have even during the kext error was still there:
- I did *not* have problems seeing or syncing the iPhone in iTunes

Some important notes:
- do *not* try to move to trash your current iTunes which was on your Mac by default - it doesn't allow you to trash it; just follow the fix steps

- do not stop implementing the fix because you found you already have the latest iTunes version - the reinstall is what is needed, not update to latest one

Config:
- MacBook Pro Retina 15" (2012)

- Mac OS X 10.8.5

- iTunes 11.4 (18), 64 bit (both before and after the reinstall)

- AppleUSBEthernetHost.kext version by date:

• before the fix: April 05 2012
• after the fix: Jul 29 2014

For what's it's worth, I received the same message "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." However, this message popped up after updating to HP Printer 3.0 software via the App Store software update. The extension I have is version 7.0 from April 5, 2012 and I'm running 10.8.5.

I've had iTunes 11.4 installed since it came out and have had no problems syncing my iPhone.

Also got the "System Extension/System/Library/Extensions/AppleUSBEthenetHost.kext" error this AM just after auto update to Macbook Pro 10.7.5

iTunes still opens, nothing wrong yet with system. I did not get an iTunes update unless it was contained in the Mac update.

FYI

Same exact "System Extension" error came up today while updating lastest HP Drivers. I was updating drivers becasue I updgraded to OS X ver. 10.9.5 and now I can't get my scanner function to work on my HP Officejet Pro 8200 Wireless A909g, which is supposed to be supported by the latest HP driver update. I keep getting:

"An error has occurred saving the file because it could not be written to. Check the properties for the file to make sure it is not read only.

This is driving me nuts. Help please, anyone? thanks,

almost forgot, everything I've read thus far speaks to this issue as it relates to iTunes. I've not yet had any problems with iTunes, so I'm afraid to apply recommended fixes since they're not specific to HP driver issues...

I also updated my HP drivers when notified by the App Store that the "HP Printer Software Update Version 3.0" was available. After updating, I got the error message:

The system extension “/System/Library/ExtensionsThe 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 installed iTunes 11.4 on Sept 10th and until I installed the new HP Printer Driver, this error message has never occurred. I am running OS 10.9.5. Like zspy7274, it has to be the result of the install of the HP Drivers causing this error message.

So far both my HP Printer and iTunes are working fine.

Thanks for the reply dataminer007. I'm glad your HP is working. I just found a way to get my scanner to work without recieving that bizarre "could not be written to..." error. I had to bring up my HP scanner utility via system preferences, then printers and scanners. I clicked on "Open Scanner" and got it to work. Previously, I was going through my HP Scan utility via my HP folder within my Applications folder located in my dock. I still can't get it to work that way, but at least I found another route.

"I installed iTunes 11.4 on Sept 10th and until I installed the new HP Printer Driver, this error message has never occurred."

That was the original iTunes 11.4 release, which biffed everything.

Apple quietly replaced that version with an updated version back on Sept. 23rd or 24th, without telling anyone.

My advice to you (and to zspy7274, and anyone else similarly afflicted) would be:

1. Trash /System/Library/Extensions/AppleUSBEthernetHost.kext
2. Reboot
3. Re-download iTunes 11.4 (I call it "11.4++") from the Apple iTunes download page
4. Re-install iTunes from the downloaded .dmg file (the .dmg file size should be 242433227 bytes - if it's 242940774 bytes, you have the old/bad version!)
5. Re-install your HP printer drivers
6. Reboot
7. ...
8. Profit!!!

Greg Earle - What version/build number shows up in your About iTunes window? Mine is 10.4 (18)

Thanks!