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

Tuxera was my only (quick) solution too. My 4TB external ExFat HD 'suddenly' stopped mounting. After reading a couple of possible solutions I did realise it probably happened when the power supply in the street was cut for couple of hours ( I always leave my MacMini in sleep). So Disk Utility did see the disk but couldn't mount it, killing fsck in the Terminal didn't work.

Tuxera (which I happened to have purchased years ago and occasionally use to write to & format NTFS drives) did the job and mounted this very important hard drive (of which I don't have a backup, ouch). Thanks for this tip!

Does the Mac recognize the drive in the System Information window (hold down the Option key and go to the  menu and select System Information)?

That was the problem for me too domagoj240. That's why I purchased the Tuxera NTFS app.

Paragon is not up-to-date for OSX

for Big Sur search for fsck_exfat

It does resolve the issue with the right extension e.g. fsck_hfs. Double click on process listed in Activity Monitor and choose quit.

This doesn't really help. I don't want to lose all the info I have on my external drive. You've made it sound like it's the drive issue but it's really with how the new Catalina update is working to read these drives. Please provide a better fix. I need drive access without reformatting & it's worked fine up till the latest update.

I recently purchased a new IMac and upgraded it to Catalina. BIG mistake!! I have this same problem and it will not mount any external hard drives. These drives all still work fine on my old macBook running Mojave 10.14.1. This problem started when I Accidentally unplugged a drive and didn't trash the icon first. Another problem is Disk Utility and some other programs will not respond to a QUIT command. The only way to get them to quit is to force quit them. I assume you will have a fix soon???

I'm having a similar issue - "com.apple.DiskManagement.disenter error 0." since the Catalina upgrade.

I've a partitioned 2Tb drive - half I drag & drop files to, the other half is for Time Machine. I have another disc that I use as a backup for the files/data but not as Time Machine.

My partition for dragging files into mounts but the Time Machine partition won't. It wt was last seen in action trying to backup a few days ago but announced it had insufficient space.

An ideas?

I'll also post on a Time Machine forum

This is really interesting..I did a bit of investigating myself. Seems like while Catalina starts, codes like "fsck -fy" would be running in the background to determine if a drive is mounting or not. I wonder if something is missing in those codes that disallowing some external disks be read (My HD is Seagate - 3TB - NTFS) or there is a link between Catalina's security code that sends a signal to your antivirus software saying that, the drive is a virus and should not be mounted. I suspects that because I formatted my Mac and it was under OS X Lion, whenever I plugged my HD in, a window of my antivirus popped up and said "blocked autorun.inf because it was infected with INF: Autorun-BH(Wm)" and I am back to Catalina with the same computer, there is no message when I plug in my HD. Yet, my drive is grey out from the list. All of my other WD drives are ok in Catalina.

I'm pretty sure it's a Catalina thing. I formatted my Seagate 5TB drive with exFAT on Windows, my Mac didn't mount it. My other WD usb drives with NTFS are fine. I reformatted the Seagate with NTFS, Mac has no problem mounting it, of course I can't write to the drive. It looks like Catalina abandons exFAT, sad!

I am running a MacMini with Catalina (current rev) and got the same error. I have an external Drobo Mini which has been working without any issues for years. But with Catalina I got this error. I ran "First Aid" (Disk Utility) without success. After that there was no indication of any disk I/O going on with the DroboMini...but 5 minutes later it spontaneously mounted itself and is good for both read and write. I have no idea what was going on in the background that caused the disk to finally mount, but I do know that I had nothing to do with it...not the result of any action I took. So the MacMini/Catalina combo seems to have a "mind of its own" and does what it will do without telling the user/owner/admin person that anything is going on. Glad it's working though I do not understand the idiosyncrasies of the process that got it working.

Your problem is related to a previously disk ejection not done properly. The disk does not mount because Disk Check is in progress, you should see fsck process in the Activity Monitor app. Unfortunately MacOS does not tell you about any progress so you try many times to plugin / out your disk.

Unfortunately my problem above is different (left the whole night and there is no disk check in background), but found software that should recover files. Its a shame that third party sw can fix this and Apple does not help in fixing APFS issue.

After trying many of these possible solutions to the following error:

Could not mount (com.apple.DiskManagement.disenter error 49153)

This https://forums.macrumors.com/threads/invalid-content-in-journal.1941721/ worked for me! I finally gained access to a 2 TB San Disk thumb drive with an HFS file system.

My 2012 Macbook Pro Retina with Mac OS Catalina was not running the FCSK process either, so that possible resolution was N/A for me.

I'm having the same issue. I am upgrading to MacOS Bigsur as soon as possible. It seems like it is only happening to users using Catalina. Someone even said that their iMac Pro running Catalina has this issue but not their MacBook running Mojave. I also didn't have this issue at all until I upgraded from High Sierra to Catalina. Either I wait a billion years for Bigsur to release, or I get support and downgrade to Mojave.