An external disk refuses to mount, com.apple.DiskManagement.disenter error -119930868.

I found fsck.hsl in the activity monitor under the 'disk' tab - I forced quit this and the an error message came up to say that the disc cannot be repaired but the drive mounted immediately and I can now copy my files to another external drive.

On my system, I just have to wait for some time till I can mount my external drive (SD, for example).

Seems like Catalina runs fsck on them if they were not safely removed last time.

Drive mounts itself after it's checked for errors. It just takes time.

UPDATE FROM TODAY: APPARENTLY THE HARD DRIVE DID IT AGAIN I GOT THE 1 DISK NOT EJECTED PROPERLY

2 CHANGED STATUS TO READ ONLY

3 I WENT ON ACTIVITY MONITOR AND KILLED THE FSCK_NTFS CMD

4 WENT BACK TO DISK UTILITY AND REPAIRED.

TOOK SOME TIME BUT THE DRIVE BECAME CAME BACK TO ITS OLD STATUS TO READ AND WRITE.

I had this same issue. I purchased a Lacie d2 10TB external hard drive which is "designed for mac". Maybe it is a Catalina thing but I was getting the same error. The first time I plugged it in it mounted and the system asked if I want to use it as a Time Machine Backup drive, and thats what I wanted. The moment i Clicked "Use as Backup drive" I was prompted with the error and now it was greyed out and I run to this issue. What worked for me in the end was formatting the drive ti MacOS Extended Journaled, and now it seems to work.

I do realize that there are many people that don't want to format their drives. This issue happened to me with a brand new drive so the formatting wasn't a big issue for me since the drive was already empty. So this tip is to them who are having this issue with new drives!

I tried the various things listed in the first couple of pages of this thread, including using Terminal to run the various commands suggested and nothing work. Also installed the Tuxera app, but nothing worked. Killing the fsck process in Activity Monitor finally did the trick for me. (Maybe the other things I did were necessary for that to work?) Yea! I am copying all my data to a new drive while I have the chance.

This is about the 3rd time I've had this issue with portable external drives, every time it seems to be a little different trick to fix it. The main problem seems to be that when typing on my lap, the cable sometimes comes loose and the drive disconnects. After this happens a number of times the drive fails even though I periodically have run the repair utility. I figure it is just the weakness of using these small, portable drives.

So I solved this by installing Tuxera NTFS. It allows your mac to read and write to NTFS devices and disks. My disk was showing up on disk utility but not on finder. Once I installed and allowed kernel access - the drive showed up and I could do my backup.

Hope that helps!

https://www.tuxera.com/products/tuxera-ntfs-for-mac/

Same problem! New WD 4TB install but didn't mount. After MUCH forum review(s) I saw a link to a WD support page that WORKED for me as I want to use this drive as a Time Machine backup. I have High Sierra (10.13.6). It is important, apparently, to use the Mac OS Extended (Journaled) choice to erase/reformat the drive but within about 3 minutes I had a fully functioning Time Machine that is now backing up my iMac. Hopefully this solves your problems, too! Good luck.

https://support-en.wd.com/app/answers/detail/a_id/8200

Try this, it worked for me:

1. With the device (disk) inserted, open Utilities → Disk Utility. You will see the disk shown as /dev/diskxax (x=numeric a=alpha) i.e. /dev/disk5s2
2. Click on View (top left of window) and select “Show all devices” from the drop-down. The name of the actual physical device will be shown (i.e. “ScanDisk Cruzer Blade... or whatever your device is).
3. The /dev/diskxax is shown under the name of the physical disk. It will present as faded (grayed out) text. It will not be mounted.
4. Select the physical disk. It will present in the main box with a red bar with the legend underneath the bar in small letters with the size of the drive.
5. Select “Erase” from the options at the top of the Disk Utility window.
6. Enter the desired name for the device and select your desired filesystem.
7. Click on “Erase” and then select “Show details”.
8. Once the erase and format of the disk is completed the disk will present as mounted and the /dev/diskxax will be shown in a normal state (i.e. not grayed out).
9. The device is now ready for use

Force quitting fsck_ext just worked for me. I think like others have said if I would have waited long enough with it plugged in I might have seen it after if finishes the fsck checks and mounts.

APPLE if you ever read these... maybe the work that "fsck_ext" is doing could be bubbled to the users to say "Be patient your hard drive is being checked for errors..." and a progress bar if possible even just the spinny kind on that dialog would help. Let us know what the machine is doing. I realize that it was most likely caused by me pulling the plug instead of hitting eject (I would love to hear a quick explain on why that works on windows but not macs). Sad fact is that I bet a lot of people thought they had a failed drive as it looks to be faulty when you plug it in. I was certainly relieved to see the folders appear again. As soon as it showed up I ran disk first aid to make sure all was good and will work hard on not yanking that cable. Thanks again to all you good folks sharing the answers to the hard questions!

Hey Guys,

Its a simple fix !!!

I faced the similar issue with my Lacie 4tb external hardrive. External disk refuses to mount, com.apple.DiskManagement.disenter error.

this mostly happens when the disk is not ejected and shuts abruptly.

I was freaked out when it happened because i was about to lose 4TB data but fortunately my patience worked the best for me.

1. Yes !!! its just Patience !!! If that error shows disconnect the disk from the macbook/imac and connect it after 10 secs.
2. This time just open the disk utility and make sure the drive is visible (but you wont be able to access it because it is not mounted).
3. ***Very Important - Please let the harddrive be, dont attempt to mount it, partition it or anything.
4. The disk and the mac will do its job and mount it once it sorts itself. More the data on the drive more time it takes. Mine was 4TB filled and it took about 30 mins and it just started showed under location and disk utility to access.

So the main key here is to be Patient. Best is to connect it and get back to some other work or better sleep :D . Waiting in front of the screen makes you really anxious and fiddling with fixes might just make it worse.

Hope it helps you guys.

(P.S This works when the disk is visible in the disk utility. Not too sure when it dsnt show up.)

SOLUTION: Same thing happened with my drive. I plugged it into a Windows machine and ran a repair on it which I was able to do, unlike on a Mac it did not want to do anything at all. After it scanned and repaired it, I plugged it back into my mac and it is now working. Good luck.

sound stupid... but make sure you are not in safety mode.

.... i had a slim external cd rom sitting on my macbook and it was actually holding shift down so when i restarted it was in safety mode... external drive would not mount.... there was also a more prominent outline around the dock. (catalina)

Open Activity monitor and forse quit there fsck_ext. Will solve issuer.

The only solution I could find was to install Tuxera. This suggestion was posted on a similar Q as the solution & it worked for me. Microsoft NTFS for Mac by Tuxera 2019

Seems mine was a operating system issue (10.15.3)

I connected the HD to a MacBook Pro running Yosemite 10.10.5 and it successfully showed up