USB and external hard drive not recognized after updating to MacOS Catalina

I just lost my 2nd external hard drive since upgrading. I'm on a 2014 Macbook Pro. Lost a brand new Seagate 5 TB, now just lost a 4 TB I've used for years. They initially worked in Catalina, but now only appear in Disk Utility but refuse to mount.

I'm having the same issue. The last time this happened I downloaded the new update and my drive stopped showing up. After browsing online for hours trying to find a solution, I finally noticed there was another software update from apple and after downloading that, my drive started showing up again. I'm having the same issue again - I just got a brand new mac and no luck with my external hard drive. Did you resolve your issue? Would love to see if you figured it out.

Very basic fix that doesn't work. None of these "suggestions" make any difference, nor does using a powered USB hub: https://appletoolbox.com/mac-macbook-doesnt-recognize-external-drives-troubleshooting-tips/ Surely apple has a fix for this as it is frustrating and not the first time I've had this issue with a Mac (had on the last update of the previous operating system). I have search all of the forums and tried every solution suggested. It is clearly a software issue as my drives worked on my Mac previously and work without issue on a PC! My Mac is a MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports) and is running Catalina 10.15.2. I have tries several drives of all brands as I own many. Will read small plug in USBs just not drives (even drives with own power supply).

Hello AmayarDM! 

Thanks for reaching out to the Apple Support Communities. I understand that none of your USB devices are being recognized by your MacBook Pro since updating to macOS Catalina. I now how important it is to have your devices recognized. 

When USB ports are not recognizing devices it can be an indication that you need to reset the System Management Controller (SMC) on your MacBook Pro. The SMC is responsible for low-level functions like the USB power. Try the steps in the article below, and let me know the results. 

How to reset the System Management Controller (SMC) on your Mac. 

Cheers!

• USB not recognized is likely due to kernel crash issues:

I have the same issue with my Macbook Pro 16' [Catalina 10.15.5] with an external M.2 SSD Adata SX8200 Pro 2TB mounted on a Icybox enclosure IB-1817M-C31.

Originally, my first file transfer has crashed my computer (kernel CPU panic) and since the SSD was not visible anymore anywhere (desktop, disk utility, etc.). I thought it was factory defective and got it replaced but it seems like the problem comes from Catalina itself.

As suggested above, I have reset SMC, NVRAM and PRAM but that didn't fix the issue: the SSD is not showing up and my Macbook pro 16' does a kernel panic crash after 100s if I left the SSD connected to it, as shown in the last 3 extract of reports below:

panic(cpu 0 caller 0xffffff8003616487): "IOSCSIPeripheralDeviceType00::setPowerState(0xffffff80570a24e0 : 0xffffff7f83ec1236, 3 -> 2) timed out after 100943 ms"@/AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/xnu/xnu-6153.101.6/iokit/Kernel/IOServicePM.cpp:5296

panic(cpu 2 caller 0xffffff801a815f27): "IOSCSIPeripheralDeviceType00::setPowerState(0xffffff808a476380 : 0xffffff7f9b0c2234, 3 -> 2) timed out after 100867 ms"@/AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/xnu/xnu-6153.121.2/iokit/Kernel/IOServicePM.cpp:5296

panic(cpu 2 caller 0xffffff8016615f27): "IOSCSIPeripheralDeviceType00::setPowerState(0xffffff807d033680 : 0xffffff7f96ec2234, 3 -> 2) timed out after 100862 ms"@/AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/xnu/xnu-6153.121.2/iokit/Kernel/IOServicePM.cpp:5296

I have also disabled "Power Nap" and "Automatic graphic switching" in System Preferences/Energy Saver as suggested in many forum threads and there https://medium.com/@canartuc/kernel-panics-in-new-macbook-pro-16-solution-is-here-2ac1d88fada7

Finally, I must precise that this external SSD is visible and perfectly working in read/write on a MB Pro 13' 2019. If the content is erased through the MB Pro 13', then the SSD will become again visible on my MB Pro 16' but without being accessible, which means that it will freeze my computer if I try to access to it (f.e. copy a file into it), kernel crash my MB after some time and eventually not show up anymore (desktop, disk management, etc.)

Please, do a fix of Catalina ASAP.

I'm convinced this is the Catalina issue and still not resolved in 10.15.2. I bought a new 16inch MBP and run into the same issues. Spent tons of time with this thing unsuccessfully trying everything and finally managed to figure out, that my issue is caused by unsupported(??) 'PremiumCord USB 3.0 -> SATA III' adapter I use to connect various HDDs to my Mac. It has worked perfectly for all the OSs except Catalina - a drive connected via this adapter is not visible in Catalina. When I use a different USB 3.0 to SATA III adapter it "magically" works now! I can honestly say that if I don't use the latest 16inch MBP I immediately downgrade to Mojave as Catalina is a disastrous release. Another significant Catalina problem is ocassional kernel_task process CPU load issue without any obvious reason, but this is not part of this topic. If you don't need Catalina don't rush it and wait for at least couple of another Fixpacks if you don't want to suffer.

I updated 2 days ago and my hard drive or USB won't show. I know it's the Catalina update because I backed up all my files just before the update onto my hard drive. no problem.

The conversion USB thing that plugs into the thunderbolt lights up, my hard drive lights up and I can hear it come to life, but it can't be found anywhere. Not in disk utilities either.

I run my own business and need these files. I don't have the time to now spend hours looking to access my files!!!! this is a joke!!

I found a work around for most of my drives (plug and play hard drives and USBs but not for my larger drive that has its own power - I updated my NTFS for Mac software. The drive that I had been using for time machine still causes the computer to restart every time its plugged in (insert eye roll emoji here). It's ridiculous that this third party software was even needed and that it didn't resolve all the issues. Apple needs to get its act together. If they showed as much interest in after sales support as they do in sales we wouldn't be having this conversation.

i just purchased a mac book pro air on dec 2019 and the apple external disk drive; everything was running great until I did the catalina update, now my mac won’t recognize it, it reads my external hard drive no problem I tried everything on line any suggestions? Or will there be another update to fis the glitch?

AmayarDM wrote:

Hi, all my USB drives and external hard drive are not being recognized after updating to MacOS Catalina. They cannot be mounted as well using Disk Utilities. I'm using MacBook Pro 2015. Please help to address this issue asap. Thanks.

Did you get this issue resolved?

NTFS is the file format for Windows— Mac can r/w with the updated software:

Tuxera Microsoft NTFS for Mac by

Paragon Microsoft NTFS for Mac | Paragon Software

I've tried every reboot listed and I've downloaded the Seagate Paragon Support, but to no avail my external hard drive is not being recognized by Catalina. Under System Report > USB I can see that it's physically plugged in, but it's not mounting.

Any other recommendations? I'm desperate.

The biggest mistake I’ve made was to update to Catalina OS from Mojave OS on my MacBook Pro 2019. I purchased an expensive docking station (Brydge Stone Pro) which is not fully functional with Catalina OS, in that certain of my flash drives plugged into the Stone Pro do not register on the Mac. I had to purchase another docking station (Caldigit) which works better with Catalina OS, but even then a DM flash drive plugged into the Caldigit doesn’t always show on the Mac when it boots up, unless I plug it in again. And another big frustration is that my audiophile DAP (Cayin N5ii) is not compatible with Catalina OS, whereas it worked perfectly on Mojave OS. Let’s hope that the macOS 11 Big Sur will be a better OS.

I took my MacBook Pro to an Apple technician at an Apple Store. He erased Catalina OS from my system, and reloaded Mojave OS. Also got a new cable for the Cayin DAP. Busy reconfiguring my system, and am happy to say that the system is now more stable and the Cayin is thus far working fine with Mojave. My MacBook came with Mojave, and am happy to be back to that OS. Clearly it would seem as if there are serious issues with Catalina. The BIG lesson learnt, I'll wait before considering upgrading to macOS Big Sur. I'll first read the discussion forums and reviews before taking that leap.

I was facing the same issue. Take you hard drive and connect it to a windows laptop and then format it to NTFS file system.

Then connect it back to your Mac. Surprisingly this time it got connected for me. Go to disk utility and format it to xFat file system. It might fail but so it again. Restart your system and hopefully it will be visible. It worked for me.

USB drives won’t mount on desktop or show up in Disk Utility, UNLESS they are plugged in, powered on, and I reboot the computer. Then it will show up on desktop and disk utility. Then I can mount and unmount using disk utility, however if I eject and unplug USB cable and plug it back in, it will spin up but will not mount again until another reboot....