System extension cannot be used warning

Since my Itunes update I am plagued with a system extension cannot be used warning .
What can I do ?

Open the Terminal in your Utilities folder. At the prompt paste the following command line:
sudo chown -R root:wheel /Systems/Library/Extensions/AppleUSBEthernetHost.kext
Press RETURN. Enter your admin password when prompted. It does not echo to the screen so type carefully. Press RETURN again.
Restart the computer.

Similar Messages

System Extension Cannot Be Used message pop-up

I just upgraded from an iMac power pc to a new iMac with snow leopard. I have an HP Photosmart B8850 printer and uninstalled the previous software driver and installed updated software. The problem is that I get a warning box with the message [ System Extension Cannot Be Used. The system extension “/system/Library/Extensions/hp/photosmartb8800series.kext” was installed improperly and cannot be used. Please try reinstalling it, or contact the products vendor for an update.] It appears that Library/Extensions is empty. The printer seems to be working properly. Do I need the system extension? If not, how can I keep the warning box from popping up?

If you are looking in /Library/Extensions for this file as your message seems to indicate, you are looking in the wrong place. Go to your Finder's Go menu and select *Go to Folder...* then type in /system/Library/Extensions
Best of luck.

"System Extension cannot be used" when starting Parallels

I'm using Parallels Desktop 4.0 to provide a platform for Windows XP on my MacBook. It works very well, but since a recent update of the package, I have been getting a message on startup which says:
"System extension cannot be used
The system extension "/Library/Filesystems/fusefs.fs/Support/fusefs.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update."
I see from other discussions in this forum that this type of warning sometimes appears, but what does it mean generically - does anyone know? So far Parallels support has suggested a couple of things including reloading MacFUSE which I'd never heard of, but they are now suggesting it's a Mac OS problem. Could it be? I need some kind of steer as to what this means and what could have caused it

Hello MaxGraphics,
You both may want to read this article before proceeding. It does give you an idea about kext files and how to handle them.
http://www.ihackintosh.com/2009/02/what-is-kextwhere-is-kext-how-to-install-kext /
Hope this helps.

HP Laser Printer message saying "System Extension Cannot Be Used"

I am trying to install a laserjet printer but while it was installing, a message came up which read, "'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." We tried the printer out and it seems to work, however, the scanner does not work.
When I got this Mac Book Pro, 4 or 5 years ago, I had a HP inkjet printer which I can never use the scanning feature because it did not work. I don't remember what the error message was, but it never worked when I tried to use it. I wonder if the problems with scanning have to do with this particular file that is supposedly installed wrongly.
We tested the printer out and it worked fine. But no scanning. It can't find the scanner.
My computer is Mac OS X - 10.6.8. The printer is HP Laserjet Pro 200 color MFP.
Anyone have any idea what I should do to fix this error? Thanks.

Open the Script Editor in the /Applications/AppleScript/ folder, copy and paste the entire following line into it, and press the Run button:
do shell script "chown -R root:wheel /System/Library/Extensions/AppleUSBEthernetHost.kext" with administrator privileges
If it doesn’t work, choose Go to Folder from the Finder's Go menu, provide /System/Library/Extensions/ as the path, throw the AppleUSBEthernetHost.kext item away, and reinstall iTunes.
(118910)

System extension cannot be used --can anyone help ?

so i spotted that the system library as well as the home library had permissions blocked for the administrator, so i unlocked all enclosed items permissions.
i already had issues being brought to senior advisor attention over 1,5 years now, about hangs and freezes. mostly hangs.
no one so far has been able to fix them.
well now spotting these warnings, after i allowed all permissions inside both libraries, have warnings show up.
i gather these are not prepperly installed softwares, but i cant figure out what softwares they could be, so i can take care of it.
so 4 warnings shows up :
System extension cannot be used
The system extension “/System/Library/Extensions/System.kext/PlugIns/Unsupported.kext” was installed improperly and cannot be used. Please try reinstalling it, or contact the product’s vendor for an update.
System extension cannot be used
The system extension “/System/Library/Extensions/System.kext/PlugIns/Private.kext” was installed improperly and cannot be used. Please try reinstalling it, or contact the product’s vendor for an update.
System extension cannot be used
The system extension “/System/Library/Extensions/IOPCIFamily.kext” was installed improperly and cannot be used. Please try reinstalling it, or contact the product’s vendor for an update.
System extension cannot be used
The system extension “/System/Library/Extensions/IOUSBFamily.kext” was installed improperly and cannot be used. Please try reinstalling it, or contact the product’s vendor for an update.

There isn't an "administrator" so who did you add and what permissions did you set.
In Get Info, they should be
system read & write
wheel read Only
everyone read only
The posix permissions, owner, and group should be
rwxr-xr-x root wheel
with ACE "group:everyone deny delete"
You may be able to recover by repairing permissions in Disk Utility, but you may have to reinstall the OS.

HT1151 I keep getting an error message when installing new software that says "System extension cannot be used /system/library/extension/IoFireWireWDHID.kext was installed improperly" I have no idea what this means and all of my software seems to install

I keep getting an error message when installing new software that says "System extension cannot be used /system/library/extension/IoFireWireWDHID.kext was installed improperly" I have no idea what this means and all of my software seems to install okay

Hello Valerie Anderson,
I'm Harry from Norton Support team. Please check the information provided in a similar thread here:
https://discussions.apple.com/message/21854775#21854775
Let me know if this helps.
Thanks!
Harry

System extension cannot be used, now no AirPort Card Installed?!?!?!?!

I have had my MBP for some time now and the other day it went into a kernel panic and after having to go through all the processes to recover it including restoring from the time capsule so that it doesn't take over 10 mins to start up an error message came up saying;
"*System extension cannot be used*"
"the system extension '/System/Library/Extensions/IO80211Family.kext/Contents/PlugIns/AppleAirPortBrc m4311.kext' was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update"
Now i cant use my airport card at all, it says that there is no airport card installed and I have spent hours on the phone to apple, done the option + command + r + p thing and had to restore my whole system off my TC with the backup disks and all.
Plz plz plz plz help, i just want it back the way it was, this is so annoying
Message was edited by: TBlank

I had the same problem. It happened to me after I updated to 10.5.6. I didn't notice the problem until I rebooted a few days later. I reinstalled the system from disk and then realized that even though it took almost an hour it didn't really install anything. So I deleted the whole /System/Library/Extensions/IO80211Family.kext and reinstalled the system again. This time it worked

Error: system extension cannot be used

I get the error "system extension cannot be used" and then it says below it:
The system extension "/System/Library/Extensions/AppleIntelAC97Audio.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update.
it says the same for:
AppleIntelAC97Controller.kext
BJUSBLoad.kext
CHUDKernLib.kext
CHUDProf.kext
CHUDUtils.kext
EPSONUSBPrintClass.kext
hpPlugInInit.kext
KLog.kext
LexmarkUSBMerge.kext
prlhidhook.kext
prl_hypervisor.kext
prl_netbridge.kext
prl_tg.kext
prlusbconnect.kext
prl_video.kext
prl_vnic.kext
RBIOKitHelper.kext
Soundflower.kext
Wacom Tablet.kext
I have done permissions repair at least 10 times in a row and it still comes up with things to repair but is there another soloution?
Also, It says i have insufficient permissions to get onto my external HD now as well.
Anything will help...

I had the same problem. Then due to another unrelated problem I did a file system check in single user mode and this problem too went away. I am not sure if it will also work for you but no harm to try.
Shutdown, restart by pressing power button. As soon as you hear the chime, press cmd-s. After a while lot of text will roll down the screen, leave the keys. At the prompt, type fsck -fy. Note the space. then hit return. If at the end of the run you get something was repaired, then run it again till you get 'OK'. After that type reboot and you will boot into regular OS X. Then do whatever you did to get this message and see if it goes away.

System extension cannot be used - on startup?

Recently, I had to repair permissions after a error cause me not to be able to login. I did a startup from the disc and got in, but now these error messages come up;
System extension cannot be used
"/System/Library/Extensions/SymIPS.kext" was installed improperly and cannont be used. Please reinstalling it, or contact the vendor for an update... and;
"/System/Library/Extensions/SymIInternetSecurity.kext" was installed improperly and cannont be used. Please reinstalling it, or contact the vendor for an update... and;
"/System/Library/Extensions/IO80211Family.kext/Contents/PlugIns/AppleAirPortCrcm 4311.kext" was installed improperly and cannont be used. Please reinstalling it, or contact the vendor for an update... and;
"/System/Library/Extensions/IO80211Family.kext" was installed improperly and cannont be used. Please reinstalling it, or contact the vendor for an update...
not to mention now it says I don't have airport card and the internet is running slower!
I have completed further repair disk permissions.
What can I do?
Thanks.

HI,
*"System extension cannot be used"*
*"/System/Library/Extensions/SymIPS.kext" was installed improperly and cannont be used. Please reinstalling it, or contact the vendor for an update... and;*
*"/System/Library/Extensions/SymIInternetSecurity.kext" was installed improperly and cannont be used. Please reinstalling it, or contact the vendor for an update... and;*
*"/System/Library/Extensions/IO80211Family.kext/Contents/PlugIns/AppleAirPortCrc m4311.kext" was installed improperly and cannont be used. Please reinstalling it, or contact the vendor for an update... and;*
*"/System/Library/Extensions/IO80211Family.kext" was installed improperly and cannont be used. Please reinstalling it, or contact the vendor for an update... "*
Is this the results of booting from your install disk and using Disk Utility to Verify the drive, or just repair permissions?
Carolyn

"System extension cannot be used" when updating iTunes

Every time I update iTunes through the standard Software Update, I get multiple messages towards the end of the installation saying:
*System extension cannot be used*
The system extension "/System/Library/Extensions/IOFireWireWDHID.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update.
This only happens when updating iTunes. Any ideas? Thank you in advance!

Hello MaxGraphics,
You both may want to read this article before proceeding. It does give you an idea about kext files and how to handle them.
http://www.ihackintosh.com/2009/02/what-is-kextwhere-is-kext-how-to-install-kext /
Hope this helps.

System extension cannot be used - GeneIOUSBCFSubclass.kext

I just installed the iTunes 9.0.2 update. Toward the end of the install, an error message popped up:
System extension cannot be used
.../SYstem/Library/Extensions/GeneIOUSBCFSubclass.kext...
But the update appeared to complete successfully.
Any ideas?

That appears to be some (antiquated?) third party driver for an external USB device.
http://www.google.com/search?q=GeneIOUSBCFSubclass.kext

HT1199 I have an Apple MacBook Pro 1,1 Mac OS X 10.6.8. I have tried to load Native Instruments Guitar Rig 4LE. It would not load and said the following. System extension cannot be used.

I have an Apple MacBook Pro 1,1 Mac OS X 10.6.8. I have tried to load Native Instruments Guitar Rig 4LE.
It would not load and said the following. System extension cannot be used.
The system extension "/system/library/Extensions/AppleUSBthernetHost.text" was installed improperly and cannot be used.
Please try reinstalling it, or contact the product vendor for an update.
I do not have a copy of the OS X 10.6.8 software. It is second hand so I have no product vendor to contact.
What can I do?

You recently updated iTunes to v.11.4? This message has popped up on many a Mac screen when this version was first made available, because this kext was obviously faulty.
You should try to download iTunes 11.4 again from Apple's website: the new version bears the same name, but this kernel extension has been updated, and the issues it was causing are now a thing of the past.
Should solve your problem, too...

What does this mean? ... System extension cannot be used ... The system extension "/System/Library/Extensions/IOFireWireWDHID.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update.

I get this message often when updating things. I have told Small Dog Computer where I buy my stuff, and they didn't have an answer. Thanks in advance.
What does this mean? ... System extension cannot be used ... The system extension "/System/Library/Extensions/IOFireWireWDHID.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update.

Interesting ... thank you! Actually I had that external drive, Western Digital, a while back on my second last? or third last? laptop ... the external drive died with a slew of pictures I had carefully uploaded to it :-(
I won't worry about it anymore :-)
sorry you got only 5 points, can't figure how to give you 10 points.

Changed Permission Settings: "System extension cannot be used"

I was having some weird problems with file sharing on my network recently, so I tried changing around some of the permissions on my drives to see if I could resolve it. For some reason I was getting messages saying I didn't have permission to copy files from one computer to another on my network. This seemed to come on randomly as we have been doing file transfers this way for quite some time now. I looked at our file sharing preferences in the System Preference's and added all 4 drives from my Mac Pro in there and made sure that my username had full read and write capabilities. I then tried logging into my Mac Pro from my iMac, just like I've done in the past, and I was still unable to copy the files. So I removed all the folders and turned off file sharing. I then clicked 'Get Info' for my main Macintosh HD and tried changing the permission settings there. I clicked the option to make my username the owner, and then I clicked 'Apply to enclosed items...' and this brought up a progress bar that I let go for about 10 minutes. Then I got a pop-up error message stating "System extension cannot be used" and had an extension path listed underneath, saying it was installed improperly and cannot be used. This happens an endless amount of times. It seems to be giving me this message for every single extension on the computer. If I hold down enter the pop-ups just keep coming with different extensions listed.
I hope someone with some insight on how permissions work in OS X Lion can give me some advice on how to resolve, and possible the correct way I should be setting up sharing if I've been doing wrong all this time. What strikes me as odd is that I never had any issues with sharing anything up until about a week or so ago, and I can't remember if there were any system updates that I installed that might have something to do with this.
Any help is much appreciated, thanks!

I had this problem recently in addition to my laptop getting stuck on the Apple logo and spinning icon. It took me a long to time to work through it so I thought I would share what I did to make it easier for others.
The best thing to do when having permission problems is to do a 'disk permissions repair'. You can do this using the disk utility app found in your applications/utilities folder. This will attempt to rewrite all the permissions that were incorrectly set. When it is doing this it is common to get a message saying 'ACL...found and not expected...' do not go and delete these files. Its normal for this correction process to take more than 30 minutes, for me it took an hour.
If this proccess doesnt work for you than you can also try a disk repair.
If you can't boot using the normal disk you can also access this program through the recovery boot (holding Command-R of Option at startup), through the safe mode (holding Shift on start up) or through a recovery CD. You can also boot in a terminal type mode but this is a last ditch effort as a misspelt command could do more damage. personally, because I do not know what the commands I am using actually mean, I would recommend talking to a person at apple then using this approach.
Hope this helps

Modem: System Extension Cannot Be Used

I made an error attempting install the modem extension from my iMac into my iBook so I could connect at more than 28,800. Now I get the following message at startup: System Extension Cannot be Used. The system extension "/System/Library/Extensions/Applel2ModemFamily.Kext" was installed improperly and cannot be used. In Network Port Configurations, the modem is grayed out. I tried to reinstall OS 10.4.8, but problem remains.
Is there any way to reinstall just this one extension?
I saw mention of doing an Archive and reinstall of the OS in another post. If I do that, will I need to reinstall all other applications, such as Virtual PC. I don't want to risk making them all not work, but would like to get modem capacity back.
Currently I have dialup on my iMac being shared via Airport
iBookG4 Mac OS X (10.4.8) 1.42 Ghz, 1.5 Gig RAM

…will I need to reinstall all other applications, such as Virtual PC
No. See http://www.apple.com/support/tiger/install/ for details, especially the one about A&I.

System extension cannot be used warning

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