"USB Devices Disabled" notification always showing

This reply may be late to the party but, for prosperity's sake, I hope it may help others who encounter this issue.

A client's Mac Mini 4,1 already had 2 non-working usb ports so I installed a powered 4port usb3 hub. Afterwards I updated the OS from Lion to El Capitan 10.11.6 to accommodate updates to Skype. This is when I encountered the dreaded notification. I tried the usual: reset SMC; NVRAM; safe-boot; check the firmware, which was up to date; visually inspected the ports for damage, nothing obvious could be seen; unplugged all the usb devices and plugged them back in individually in the 2 working ports–all to no avail. I looked through the console logs and found that the usb port throwing the error was one of the dead ports which made sense since all the peripherals were working normally, it was only the notification that would not go away and was a causing slow down to the system. Like everyone else I scoured the net for a resolve and my last resort was, as mentioned here, to turn off notifications; which was not an issue with the client. The difference is I did it through the terminal with the following code found in another forum. The notifications have stopped and the mac is running smoothly now. What I haven't done, yet, is turn it back on...maybe next time I am called back I will do that and report back. Here is the how:

Use this code to disable the User Notification Center plist for about 1 hour without shutting down:

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.UserNotificationCenter.plist

Then re-enable with this code:

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.UserNotificationCenter.plist

As always any code applied in the terminal is done so at your own risk.

I have the same problem.

The solution i found is to turn on "Do Not Disturb" from Notification Center

Im having this exact same thing ever since updating to EL C. My external hard drive works ok in both my usb ports on my macbook pro 13" 2014 but when i come to plug my PNY Card reader in which i need to do desperately it doesn't work in either ports which it was working fine just before updating, changed cables and still no luck apart from "USB devices disabled"

Any ideas ?

Im having this exact same thing ever since updating to EL C. My external hard drive works ok in both my usb ports on my macbook pro 13" 2014 but when i come to plug my PNY Card reader in which i need to do desperately it doesn't work in either ports which it was working fine just before updating, changed cables and still no luck apart from "USB devices disabled"

Any ideas ?

Leonidas Kalantidis wrote:

I took it to be serviced, they asked for more money than I could spend to change the logic board. Instead I found a Thunderbolt to USB adapter and moved on like this.

One repair option is to ask about their "Flat Rate" repair depot. This is a less expensive option where the Apple Store send the Mac to their repair depot, there are several tiers but any and everything is repaired for the flat rate.

Add my name to this list.

MacBook Pro (13-inch, Mid 2010)

Upgraded to OS X El Capitan (10.11) on 09/30/2015, first login, and every login since.

USB Devices Disabled

Unplug the device using too much power to re-enable USB devices.

Nothing is plugged into the USB ports.

Currently, using the "Do Not Disturb" workaround.

This behavior did not exist prior to the El Capitan upgrade.

I hope APPLE read this comments. I'm having the same issue after updateing my software to EL CAPITAN on my IMac. it doesn't matter if I have my keyboard connected or not (i even tried different keyboards). After upgrading to EL CAPITAN i keep getting the same annoying message. USB Devices Disabled: Unplug the device using too much power to re-enable USB Devices.

How do we fix this? How can apple fix this bug or it created on my iMac?

Any tips would be amazing! And I don't want to pay for something I didn't even brake.

Yep I just upgraded to the new OS X about 10 minutes ago and they keep popping up!

Same here - on a 2012 Mac Pro. I have a few startup drives in this machine. Did an SMC reset - left it unpowered for over 20 minutes - and it worked on one. A ten minute one did NOT work on the other drive - same machine. I'm about to turn it off and try a longer one. An SMC reset is done differently on a Macbook Pro - you'll have to look it up on the web - but you might want to try that first. If I figure out anything else, I'll post here.

Did a longer SMC reset. Did not work. THEN, I unplugged each USB device. I am only use the three rear ports on this Mac Pro. Two of them did not set off the warning. The third one - my Mattias keyboard - DID invoke this notification. I then tried it with an Apple keyboard and another Mattias one. Neither one set it off. I guess I'll live with this for now.

I have same problem. Upgraded to El Capitan last night. Have no USB devices connected, but same persistent message appears. Turned off notifications and it went away.

Same thing happening to me. SMC reset, unplugging all USB devices, nothing got rid of the message.

Interestingly, like the OP, for a few years I've been having problems with USB on my iMac. the two middle USB ports of the four haven't worked for years, only the two outer ones do. But I only need two, I've made do. So I wonder if the message has something to do with a change in El Cap, it's detecting an error that it never previously did?

I tried so many solutions what works for me is:

shut down the computer, and then turn the computer back on.

Hold the "Command-Option-P-R" keys together before the gray screen appears until you hear the startup sound for the second time. Release the keys.

let me know if it works for you.

Regrettably, it did not work for me. Thank you for sharing, though.

I tried this method and it did in fact solve my problem with the usb port. Thank you!