system extension cannot be used AppleUSBEthernetHost.kext

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.

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.

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.

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

Same here, but I'm using the "iTunes 11.4++" version from Sept. 23rd.

There's no guarantees that the older, original iTunes 11.4 release (from September 9th or thereabouts) doesn't also say "10.4 (18)" as well.

If dataminer007 hasn't changed his original Sept. 10th iTunes 11.4 install, maybe he could check the version/build number to confirm/deny?

"I just reinstalled the latest version of iTunes and the HP drivers per Greg Earle's instructions, so I can't confirm the build of my previous version of iTunes."

D'oh!@

(On a more hopeful note, did that fix your problem? Also - what vintage Mac and OS is this on?)

Greg,

You were correct when you said "vintage". 7 years is a long time time to have a computer. This is my 4th iMac and it seems that I am able to keep them longer and longer. But it is time to upgrade.

BTW, thanks to everyone and especially Greg. This is a wonderful resource to have.

"I have a 20 inch mid 2007 iMac Processor 2.4 GHz Intel Core 2 Duo, Software Mac OS X 10.9.5 (13F34)."

OK - good to know. Just checking to make sure you didn't have a 32-bit-only, 2006-vintage Core Duo-or-older system.

So we know that 64-bit capable (like your Core 2 Duo iMac), Mavericks-running machines can also get these same "The system extension “/System/Library/Extensions/AppleUSBEthernetHost.kext” was installed improperly and cannot be used." error messages as well.

The important thing is that for these systems, knowing that trashing the now-damaged AppleUSBEthernetHost.kext and re-installing iTunes 11.4++ and whatever other software (be it HP drivers or otherwise) that provoked the error will now fix the issue.

(USB tethering is probably still broken even on those "newer" 64-bit systems, but at least those could potentially be fixed - 10.6.8/32-bit owners are stuck.)

I looked through /Library/Receipts/InstallHistory.plist for installation dates and found out that my iTunes was updated by Software Update to 11.4 (18) on 2014-09-16. Thus the build numbers are the same for the original and for the later iTunes 11.4 versions, the one Greg calls "iTunes11.4++". There was no error message regarding AppleUSBEthernetHost.kext at that time.

Two weeks later I installed the HP Printer Software Update version 3.0 on 2014-10-02 and immediately received the kext error. The HP update caused a rescan of the extensions and that's when the system recognized that the AppleUSBEthernetHost.kext, apparently introduced by iTunes 11.4, was faulty. Looking through previous system logs I find these entries at the time of the HP update:

Oct 1 20:52:28 Aptas-MacBook-Pro.local com.apple.kextd[12]: Rescanning kernel extensions.

Oct 1 20:52:28 Aptas-MacBook-Pro.local com.apple.kextd[12]: Cache file /System/Library/Caches/com.apple.kext.caches/Directories/System/Library/Extensi ons/KextIdentifiers.plist.gz is out of date; not using.

Oct 1 20:52:28 Aptas-MacBook-Pro.local com.apple.kextd[12]: Cache file /System/Library/Caches/com.apple.kext.caches/Startup/IOKitPersonalities_x86_64. ioplist.gz is out of date; not using.

Oct 1 20:52:30 Aptas-MacBook-Pro.local com.apple.kextd[12]: Can't load AppleUSBEthernetHost.kext - authentication problems.

Oct 1 20:52:30 Aptas-MacBook-Pro kernel[0]: Resetting IOCatalogue.

and right after the HP installation:

Oct 1 20:52:44 Aptas-MacBook-Pro.local com.apple.kextd[12]: Rescanning kernel extensions.

Oct 1 20:52:44 Aptas-MacBook-Pro.local com.apple.kextd[12]: Cache file /System/Library/Caches/com.apple.kext.caches/Directories/System/Library/Extensi ons/KextIdentifiers.plist.gz is out of date; not using.

Oct 1 20:52:44 Aptas-MacBook-Pro.local com.apple.kextd[12]: Cache file /System/Library/Caches/com.apple.kext.caches/Startup/IOKitPersonalities_x86_64. ioplist.gz is out of date; not using.

Oct 1 20:52:44 Aptas-MacBook-Pro.local coreaudiod[287]: Enabled automatic stack shots because audio IO is inactive

Oct 1 20:52:46 Aptas-MacBook-Pro.local com.apple.kextcache[6764]: rebuilding /System/Library/Caches/com.apple.kext.caches/Startup/kernelcache

Oct 1 20:52:46 Aptas-MacBook-Pro kernel[0]: Resetting IOCatalogue.

Oct 1 20:52:47 Aptas-MacBook-Pro.local com.apple.kextcache[6766]: AppleUSBEthernetHost.kext is not authentic; omitting.

Oct 1 20:52:51 Aptas-MacBook-Pro.local com.apple.kextcache[6768]: / locked; waiting for lock.

"I looked through /Library/Receipts/InstallHistory.plist for installation dates and found out that my iTunes was updated by Software Update to 11.4 (18) on 2014-09-16. Thus the build numbers are the same for the original and for the later iTunes 11.4 versions, the one Greg calls "iTunes11.4++". There was no error message regarding AppleUSBEthernetHost.kext at that time."

That's why this stuff is so insidious. Apple quietly updated the installer, didn't tell anyone, and didn't change the "visible" version number (i.e. the "11.4 (18)") for anyone to notice it was subtly different. You literally had to go down into some .plist files to see the slight change in some versioning variables to tell.

BTW I am a pack-rat so I still have a few old versions lying around. The newer iTunes 11.4 .dmg actually got smaller than the original by almost 1/2 a MB.

[17:02] nightowl:/<2>Disk images/iTunes % ls -ltFr

total 1631408

-rw-r--r--@ 1 earle  staff   14507195 Oct 12  2006 iTunes5.0.1.dmg

-rw-r--r--@ 1 earle  staff   58621179 Sep  9  2008 iTunes8.dmg

-rw-r--r--@ 1 earle  staff   98180859 May  2  2010 iTunes9.1.1.dmg

-rw-r--r--@ 1 earle  staff  178545308 Jun 13  2012 iTunes10.6.3.dmg

-rw-r--r--@ 1 earle  staff  242940774 Sep  9 05:52 iTunes11.4.dmg

-rw-r-----@ 1 earle  staff  242433227 Sep 25 13:17 iTunes11.4++.dmg

(Look at the progression of the file sizes. Bloatware, anyone?)

"Can you confirm that this fixes the missing iPhone-as-a-network-connection problem? When I have my iPhone plugged in via USB, it does not show up as a network interface for tethering. I can only use the iPhone for tethering over Bluetooth or Wi-Fi."

No, it does not fix USB tethering.

The AppleUSBEthernetHost.kext that comes with iTunes 11.4 (or "11.4++") is busted, just like every version of the .kext since back to at least 2.3.0 or maybe even 2.2.0. 😟