No Mountable Systems Dmg Fix

Jan 08, 2012  I have a Mac and I tried to download Steam, however when I click on the dmg. File I get a popup saying that there are No Mountable File Systems. What does this mean and how do I fix it?

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Kelly Heffner Wilkerson
November 8, 2019 at 6:30 AM
Categories: macOS View Comments


I ran into an interesting macOS error while working with a customer a couple of weeks ago. I didn't find a lot of good search results addressing the issue, so I decided to write up a post about it myself.

No Mountable Systems Dmg Fix Pc

No Mountable Systems Dmg Fix

The error was as the screenshot above shows; trying to open a dmg (disk image), macOS showed the error 'no mountable file systems'. If you see the 'no mountable file systems error' while opening a dmg, here's what you should try:

  1. In most cases, the downloaded dmg file is actually corrupt or had an error downloading. If possible, try downloading the dmg again, turning off any download assistant plug-ins you may have. You can try downloading the file in a different browser as well. Or if you don't need to be logged in to the site to download the file and you want to be fancy, you can try curl -O url in Terminal to download the file. (There's an example of that in my screenshot below.)

  2. Reboot your Mac if you haven't already tried that. Apparently there is an issue sometimes after opening too many dmg files, that is fixed with a reboot.

  3. Try mounting the DMG on the command line in Terminal. We will at least get some sort of useful error message to go on if it still fails:

    • Open Terminal: In Spotlight, the search magnifying glass at the upper right corner of your screen, search for Terminal, and press enter to open the Terminal app.

    • Type hdiutil attach -verbose into the terminal. Add a space at the end, but don't press enter yet.

    • Drag the dmg file from your Finder window onto the Terminal window and let go. This will fill in the location of the dmg file into your Terminal window.

    • Press enter.

  4. macOS Sierra (10.12) and earlier is not able to mount the new Apple File System (APFS). So if you're on macOS Sierra (10.12) or earlier and you ran hdiutil and see references to Apple_APFS or error 112, the issue is likely legitimate incompatibility, and this disk image won't open on this Mac without an update to the operating system.

    Here's an example of the end of hdiutil attach -verbose output that shows an APFS error due to an older version of macOS:

  5. Think about if you have any kind of security policies on this machine to prevent writing to external drives (thumb drives, optical drives, etc). I haven't seen this one in action, but I read about this being a possibility while researching the issue.

  6. Another suggestion added by a reader (thank you, Markus!) is that filesystem errors on your main Mac drive could be the cause of the disk image mounting errors. Here are instructions from Apple for scanning and repairing errors using Disk Utility. Note that in order to scan and repair errors on your main Macintosh HD drive, you'll need to reboot your Mac into recovery mode. You'll want to choose Disk Utility in the utilities listed in the recovery mode menu.

  7. A new discovery from a reader (thank you, Colby!) is that APFS DMGs won't mount if you're booted in macOS booted in Safe Mode. (Who knew!?!) If you're not sure if you're in safe mode, select the Apple menu  > About This Mac > System Report button, then select the 'Software' heading from the left column. To exit safe mode, restart your Mac, without holding Shift during startup. Or, if you previously set your Mac to always boot into safe mode using nvram, turn off safe mode and have your Mac boot normally on the terminal:

    • Open Terminal: In Spotlight, the search magnifying glass at the upper right corner of your screen, search for Terminal, and press enter to open the Terminal app.

    • Type/paste sudo nvram boot-args=' and press enter.

    • Restart your Mac.


Force-mount unmountable disk images 16 comments Create New Account
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No Mountable Systems Dmg Fix Windows 10

Great, Great, Great.
I am creating a lot of disk images at the moment for the distribution of a product and obviously I have to test those images. After mounting about 10 the Finder stops doing it's work as described in the hint. This problem exists even in 10.3.5 and I am very happy now, cause rebooting, the only solution I had figured out so far, really interrupts my work big time.
Thanks for the tip.
---
DubMaster
--
Rehab is for quitters!

I have an image that is password protected, and it still doesn't mount with this hint. Here's the output from terminal. Since the GUI password box came up on the display, I suspect that whatever OSX bug the command line evades is non-evaded when the PW function is called. Another encrypted image that mounts ok in the standard way (double-click) mounts fine using hdiutil. Haven't tried rebooting to see if that lets me mount the first image.
AppleScript to Force-mount unmountable disk images
It just so happens that we already built an AppleScript solution using this method; I'll paste it below for those who are Terminally challenged. As for the issue with password protected disks, this script will indeed trigger a GUI window asking for any such passwords not already stored in Keychain. I have yet to find an instance where presentation of the password box triggered the failure we're looking to overcome in this hing, but the -stdinpass switch would likely resolve it (see the man page), and could be added to this script. Sorry about the code wraps, Rob, I tried to install AS returns, but they wouldn't deal with the line wraps any better because of the parentheticals.
AppleScript to Force-mount unmountable disk images
[Rob, you can delete the post above (when are we going to get edit privileges?) if you want; I modified the script to fit nicely--F]
It just so happens that we already built an AppleScript solution using this method; I'll paste it below for those who are Terminally challenged. As for the issue with password protected disks, this script will indeed trigger a GUI window asking for any such passwords not already stored in Keychain. I have yet to find an instance where presentation of the password box triggered the failure we're looking to overcome in this hing, but the -stdinpass switch would likely resolve it (see the man page), and could be added to this script.

No Mountable Systems Dmg Fix Download

AppleScript to Force-mount unmountable disk images
Man, it is amazing how fast folks around here report bugs. Sorry for the oversights; the script was originally written for single DMGs, and I added multiples without really testing it or thinking it through; also we rarely use a special character in a file path because we're so used to working on the web. All bugs should be resolved, except those idiosyncracies that exist with name problems in hdiutil (such as 'image already specified' errors).
AppleScript to Force-mount unmountable disk images

Now, if you could add an 'on open' handler that handled drag-and-drop, you'd be all set! Just drag your dmg files onto the script and they would mount. No file dialog to get in the way. :-)

AppleScript to Force-mount unmountable disk images

Hi there..
Well, I tried both versions of your script on several disk images (including one that I KNOW mounts fine by itself), and most of them were grayed out in my file dialog. My first thought was that perhaps they were corrupted, but at least one of them mounts fine on its own, and it was not accessible either.
I very much appreciate your scripting skills, but do you have any idea why I might be having such problems? Any suggestions from anyone else out there? I would really appreciate the help!
Thanks in advance,
mlaurenc

AppleScript to Force-mount unmountable disk images

I may just be a big newbie, (and I undoubtably am), but when running this script the only items I could select when it asked me which DMG I wanted to mount were file folders and no DMG files. Even with a foler selected, 'Choose' never highlit. Am I doing something wrong?
Also, is there an applescript super newbie thread I should be hitting up before getting to knee deep in this?
by the way, rebooting still didn't allow me to mount the DMGs. I'm running 10.3.7.
Thanks for any/all help guys!
-Seth

AppleScript to Force-mount unmountable disk images

I may just be a big newbie, (and I undoubtably am), but when running this script the only items I could select when it asked me which DMG I wanted to mount were file folders and no DMG files. Even with a foler selected, 'Choose' never highlit. Am I doing something wrong?
Also, is there an applescript super newbie thread I should be hitting up before getting to knee deep in this?
by the way, rebooting still didn't allow me to mount the DMGs. I'm running 10.3.7.
Thanks for any/all help guys!
-Seth

While this is a nice workaround - I really wish the problem would be solved instead. Very annoying. Download bootable mac os. On my machine - happens everyday after about my tenth disk mount. The image actually appears to get mounted and appears in /Volumes but it shows up no where else and is impossible to access.

I must say, it doesn't happen much with me. But if it shows up in /Volumes, you should be able to refresh the finder by doing 'disktool -r'. I am writing a script that triggers mounting of dmg and the 'disktool -r' seems to solve some of my problem.
Good luck

No mountable systems dmg fix windows 7

I tried this Hint for the first time today, but I didn't appear to have the relevant utility. Typing in hd and tab brought up
hdiutil
which is not the command quoted in the actual command string in the Hint.
Anyway, I tried hdiutil, and it tried to attach the dmg, but failed with the same problem: no mountable file systems. <sigh>
Back to restarting..
from Clytie, still having trouble
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Clytie Siddall -- Renmark, in the Riverland of South Australia
iBook G3, 10.3.5, all updates current

Yeah, 'hdituil' is a typo.

Unfortunately, this didn't work for me. :-(
---
Ron

No Mountable Systems Dmg Fix 2

I tried the applescript but nothing is highlight-able
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Infants are born. Children learn as they grow. Knowledge is power. Information in the wrong minds is deadly!!!

No Mountable Systems Dmg Fix Free

Same here
It won't work
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Infants are born. Children learn as they grow. Knowledge is power. Information in the wrong minds is deadly!!!

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