"USB Devices Disabled" notification always showing

I've been having this problem for weeks now. I have a two months old Macbook pro which has seen next to no use. The problem occurred when i first plugged in a memory stick and took it out. In my case this has nothing to do with El Capitan as I was, and still am, on Yosemite (my wife's laptop I'm talking about). But the strange thing is that both usb ports are working perfectly fine. (They are not disabled though the message says they are.) I've been to a Genius Bar and they reinstalled the OS from scratch in the hope that would solve the problem. It didn't. Nor did the SMC reset. System diagnostics performed at the Store found no fault. Yet the message keeps popping up 80% of the time after the machine wakes up from sleep. I'm finding it impossible to get a new appointment at the Apple store due to them being swamped with bookings...

I JUST upgraded to 10.11 (15A284) on my MacPro 3,1 and I'm having the same USB nag issues with my IOGEAR KVM GCS1644. The Dual View KVM works great with Mavericks and Yosemite. As soon as I upgraded to 10.11, it started the nagging....

Initially the USB keyboard and mouse connect (an Apple keyboard... btw) worked for about 2-5 minutes, then they stopped. I even plugged them into a USB 3.0 card I have installed which has supplemental power provided to the card, and the nag is there.

There is something messed up with their USB driver that isn't behaving correctly on 10.11. Initially I love the speed and performance, it's GREAT on my MacPro3,1, but I have 3 other mac's connected to this KVM, so not having this working is not an option so I'm going back to Yosemite till Apple get's off their but and fixes things...

</-Gary>

I have faced with the same problem on El Capitan - after several seconds my USB-midi device has stopped. I can see it in USB-settings, but there is no signals from it. On 10.10 everything was working well.

And new update OS X 10.11.1 doesn't resolve my problem.

Well, for me the end of this road has finally been reached. I'd got an appointment at the Apple Store and they performed a couple of hardware tests on my machine. The first one was passed with no error found. But when they tried to erase the SSD they couldn't which pointed to the fact that the SSD was at fault. (The guy told me that in this case my SSD would sooner or later fail to reboot completely). This was a new machine still under warranty so they promptly suggested a replacement and, of course, I accepted it. So... If you are having this message don't get palmed off by any work-around but insist on them getting to the bottom of it. Despite what they like to tell you in the beginning this not at all unlikely to be a hardware issue. In which case, depending on how old your Mac(book) is you might qualify for a replacement.

I tried just about everything to fix this problem on my 27" iMac running Yosemite. This included reinstalling the OS, testing the hardware, running disk repair, resetting the SMC, and resetting PRAM...and nothing worked. In my case I got the message whether there were any USB devices plugged in or not. I noticed that the computer was also quite sluggish at times.

I finally downloaded and ran one of the free virus checkers (Bitdefender) and found that indeed there was a little something going on. Since deleting this thing there have been no further USB disabled notifications and the computer is running significantly faster.

Dan

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.

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

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.

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!

Adding my name to the list. MacBook Pro 8.1, no USB devices attached, and the problem began when I upgraded to El Capitan.

Not sure about why it isn't working for others, but the "Command-Option-P-R" reset appears to have worked for me on my Mid 2012 MacBookPro i7 system.

I wrote to the apple support about this problem, and they told me to restart SMC Controller on my macbook.

And it helped me!

i too have the same issue. reverted back to yosemite on my 2008 iMac.. hope Apple comes out with a solution soon.

Unfortunately reseting SMC and NVRAM doesn't helped me.