Q: Apple USB Ethernet Host unusable

I had the same issue. iPhone was not recognized in iTunes. I'm not very familiar with using Terminal and was unable to resolve the issues coping the commands into the terminal box so I just did it manually.

1. I followed the path: /System/Library/Extensions/AppleUSBEthernetHost, dragged the file AppleUSBEthernetHost to the trash

2. Redownloaded iTunes from the Apple site

3. Reinstalled iTunes

4. Restarted my computer

5. All is working fine now.

Hope this helps!

Apparently, it's the 32-bit version of this kext that's broken, or missing, so if your Mac is 64-bit, reinstalling iTunes probably fixed the issue. For 32-bit Mac users, on the other hand...

These steps worked for me. Thank you!

Well, I the suggested steps:

1) deleted the AppleUSBEthernetHost extension

2) downloaded and installed iTunes 11.4 from apple site

3) rebooted

I can sync my iPhone now; the errors that were occurring there have stopped....

but, the inexplicable "Failed to create replacement string" messages still appear in the system log... sometimes dozens or hundreds of times per second.

iTunes 11.4(18)

OS X 10.9.5

How do you access the system log?

I am running 10.8.5 on an iMac 2.93 GHz Intel Core i7 from about 2010

SCH1982 wrote:

 

but, the inexplicable "Failed to create replacement string" messages still appear in the system log... sometimes dozens or hundreds of times per second.

 

I'm seeing that entry in the log, too. Annoying, but I'm just going to ignore it. Apple will eventually fix it. Or not.

vikvf wrote:

 

How do you access the system log?

 

The easiest way to view the system logs is by using the Console app that is found in Applications | Utilities.

Unless this is a notation style I'm unfamiliar with, I think I may have spotted where the problem with the iTunes 11.4 installer is located. Is it just me, or are there not supposed to be two slashes in front of "//System/Library/Extensions/AppleUSBEthernetHost.kext"?

My two cents is in keeping with the rest of the posts in the forum: delete the extension in this location (requires an admin password to do so), download and re-run the iTunes 11.4 installer and restart. With the .kext file deleted, the installer does correctly reinstall the missing file. I am not currently working on any Macs that use a USB-based Ethernet adapter, so I can't verify whether or not that part of the system still works, but I don't get the same error when reinstalling iTunes, so I hope all is well.

My guess would be the opening double slash indicates the top of the tree, i.e. the persons computer. And everyone may have a different name for the top of the tree.

Funny, I haven't seen that error message in a while. AND I note that tere has not been a 11.4.1 release, so it seems this is not considered a serious enough issue... except for users bitten by it! Further, my guess is the vast majority using Mac computers do not regularly prowl through these boards, so MANY may have no idea of the work-arounds listed here.

any other suggestions for getting to that path?  i attempt to go there and there is no extensions within library, systems...having some serious issues trying to restore my new iphone 6!

running a 32 bit macbook with 10.6.8....

"any other suggestions for getting to that path?  i attempt to go there and there is no extensions within library, systems...having some serious issues trying to restore my new iphone 6!

running a 32 bit macbook with 10.6.8…."

ASLL001, I'm wondering if you are looking in the wrong library. Try this….go to the GO menu in your menu bar, scroll down to Computer, select your hard drive ( if you didn't rename it, it is probably Macintosh HD), then select System, then Library, then Extensions, then look for that file. If it is NOT there, that could still be a problem because I believe it is needed to connect your iPhone via USB. If it is not there, I'd still try downloading iTunes from the web, and reinstalling it. I should mention, I keep my iTunes folder in the SHARED folder on my hard drive rather than in my USER folder so all users have access to it.

I'm running 10.8.5

If you just got a new iPhone 6, you have free tech support for 90 days so you might try calling  1 (800) MYAPPLE. If you don't feel like you are getting any answers with the person who helps you, ask for a senior tech advisor. I often find I need to do that because I often find i know more than the people initially answering the phones.

Good luck!

thanks for the above. i was able to remove it and reinstall itunes...but still no luck. interesting enough when i plug in my phone the computer launches iphoto but no itunes.  I manually open itunes up and my phone connects, just doesnt allow me to sync or make any changes.

apple support is the next step i guess....

thank you!

One last thing….did you restart? Let us know how your support call goes….

OK! I got a senior tech support agent tonight --- 1hr 45mins on hold/with support.  first we tested if it was the computer or the phone. But realized that my iPad would not sync either -> signaled the issue was with iTunes.  We did a test user to see if the iTunes on the test user account was up to date (which it was). Then we did a file system check in single user mode which fixed something -> i wont provide the coding as I don't want to be responsible for messing with that!  after that was completed we deleted iTunes and moved it to the trash (without emptying, no clue if that matters).  Followed up by going to the Apple.com and downloading iTunes and installing it.

After that it worked....not sure what exactly was done differently with the tech support than what i did besides the system check (I did delete the kext file last night on my own without the tech support and deleted itunes and re-installed it).

but hey, everything is working and i just sync'd up.

running 10.6.8 on a 2 GHz Intel Core Duo

I'm assuming everyone on this thread knows by now, but Apple silently replaced the iTunes 11.4 .dmg file on the Apple iTunes download site with a newer version dated September 23rd.

I would advise everyone reading this to re-install iTunes 11.4 (I call it "iTunes 11.4++") from this new version.  Most problems are apparently fixed with this newer release.  (Why Apple didn't advertise it, or call it iTunes 11.4.1, I'll never know.  Grrr ... )

If however you are still on an old 32-bit only computer running Snow Leopard 10.6.8, the AppleUSBEthernetHost.kext kernel extension is still 'broken' even in this newest version - as it is still 64-bit only.  (The previous version that came with iTunes 11.3.1 was dual-architecture.)

Hopefully none of you on a 32-bit 10.6.8 machine have an Apple USB Ethernet Adapter