External hard drive not mounting Mac

Just got a 2TB drive, attached in a dock. System says can't read it do you want to initialize or ignore, so I initialize and nothing happens. Open Paragon's NTFS program and use it to erase and format with HFS+. It's on my desktop, won't show up in DIsk Utility, drag a file to it, adds it just fine, still nothing in Disk Utility...Need to partition it. Just weird. Heading for a restart..Apple is losing its mojo, especially with the root access no password issue, wow.

I just did the upgrade to High Sierra today and found my external Seagate 2T (NTFS) drive not mountable, even through Disk Utilities. The problem was the old NTFS driver I had installed. I uninstalled it and the disk is mounted, and of course it is mounted as a read-only, and all my files are there. I tried to install the NTFS driver from Seagate Dashboard and it says it is not compatible with the current version of the OS. I guess I can only wait?

Thank you Matthew but my drives do show up in either view (All devices and Volumes only) however they cannot be worked with at all. They show as mounted but they cannot be unmounted.

They also show as 1.8TB instead of the 4TB drives they are.

Very frustrating.

I'm not used to post an issue: but same situation for me.

Rebooting did not fix, and my dongle works.

I took another USB key (same issue) then formatted it to fat32 (needed it to be read by a printer).

But it is not readable by any device apart my own computer!

Let's be honest: it becomes more and more difficult to stay patient with all macOS, iOS bugs theses days...

Hello,

I had the same problem after High Sierra upgrade: impossible to mount the external hard drive (brand new Touro 2TB). After reading these posts, I tried to reboot the laptop without success. Using the laptop of my girlfriend (still on Sierra) I was able to mount and format (Mac OS Extended) the hard drive. Done that, I was able to mount it on my own laptop; I re-formatted it, just to see if there were some other problems before using it for time machine backup.

Hope this post can help you guys,

A+

The only thing that worked for me was to leave the SD Card inserted and then restart my Mac, it mounted as usual after it restarted and I was able to download all the photos from my camera to my Mac. (The key here is to leave the disk plugged while restarting, I restarted unplugging the disk first and that didn't work.)

Thank you to whoever suggested this solution, the more complex ones didn't work, and I didn't want to first aid it because I know it wasn't a damaged disk.

This happened after I updated to MacOS HighSierra version 10.13.2 (17C88)

I hope this helps.

I had this problem too (and was freaking out!) I could see the ext hard drive was there, but it said the destination was not found and I could not access any of the files.

I opened a new window to see the devices menu, and right clicked on the Ext HD, then "get info".

In the bottom right corner there was a padlock symbol, which I had to press. Then it just asks for your password.

This seems to have fixed the problem.

It's deceptively simple, so I thought I would post in case anyone else had the same problem.

I had a similar issue with the WD 1 TB after upgrading to High Sierra. I went to WD website: My Passport for Mac | WD Support and downloaded their utility tool. I ran the tool, erased the hard drive and got it working again.

I have 2 Seagate external drives connected via USB that have a GUID partition map and they mount / unmount successfully. However a WD My Book, connected via Firewire with an Apple partition map used as a Time Machine backup is greyed out in Disk Utility and won't mount. I have tried a restart without success. I have run First Aid on the device and it reports 'Operation successful'. Has anyone any thoughts on a solution?

Thank you so very much for sharing this!

It saved my neighbour (who had the same problem and to whom I just showed your post) hours of frustration and a long trip back to the store (it is a brand new drive which he was unsuccessfully trying to reformat)

So again, thank you !

Excellent! I have been looking for this solution for several months. I tried clicking all devices and I could erase the USB external physical disk. The USB external volume showed up and could erase.

Both the expensive 1 TB SSD are working and all is well.

Thank you much!

Thank you so so much, I had already spent a few days trying and trying different methods, to fix this, and this did it. super simple. I really appreciated that you posted this. I had the same issue, I wasn't able to erase it, partition it, nor use the first aid or anything my WD external drive was not mounting, and it was grayed out. But after I did this, I went to View>Show All Devices and then reformat it to MacOS Journaled and it Works now!!🙂 perfectly fine, this totally fix it, I was already thinking in getting a new HD, thank you once again.

Thank you soooooo much for posting this. I had a similar problem - external disk (mac os extended) wouldn't mount on a brand new MacBook Pro with OS13.2, but I could see it greyed out in disk utility, and I was at a loss as what to do. But as soon as I clicked "Show all Devices", the drive suddenly appeared in finder, no problems at all. I did not have this problem with another drive - but that one was mac os extended journaled, not sure why that would make a difference in terms of it mounting, but oh well . . .

Matthew, I was tearing my hair out trying to work out how to fix this - other threads had others with the same problems and no obvious or easy answers but this has done the trick. Thanks, I was up the creek without a paddle otherwise!

Yes great to solve. But why do you have to spend hours trolling forums trying to find such a simple answer as this to a problem created but bad software design.

Why wouldnt it just work that way in the first place and what does the current design exist at all

sometimes I yearn for the simpler days back in windows

and why doesn’t apple fix these stupid things.