"Error Message" when opening software on MacBook Pro M2 Chip, How to fix?

I'm having the same issue on my M1 Mac Mini, but with using google chrome.

At first, Google Chrome stopped working, period. So I deleted it, and re-downloaded it. When opening up the installer package, I got the same error: "The disk image couldn't be opened. Failed to mount filesystems."

Is that Mac MDM managed as MosyleSecurity.app hints (Mobile device management )? Is it your own Mac or a Mac managed by a school etc?

If so, maybe that is interfering with .dmg mounting?

> I tried to download Firefox and when I tried to open it I get the same message

...hmm maybe there is something wrong in your setup because that same Firefox .dmg opens OK for me.

Does it work in other user account?

Remove all 3rd party virus apps (Avast, AVG, Bitdefender, Intego, MacAfee, Norton, ESET NOD32, Trusteer etc) and 3rd party "cleaning", "optimizing", "speed-up" apps (CleanMyMac, MacKeeper etc). They produce only obscure errors and money loss.

An EtreCheck report would eliminate much guesswork:

Using EtreCheck to Troubleshoot Potential… - Apple Community

How to use the Add Text Feature When Post… - Apple Community

Try booting into Safe Mode to see whether you can now mount the contents of the .dmg file. If so, then it means you have some third party software installed which is interfering with the normal operation of macOS. Usual culprits are anti-virus apps, cleaning/optimizer apps, and third party security software...none of which are needed on a Mac.

I'm assuming the .dmg file is located in the Downloads folder?

Unless it is an issue with some third party software, or other modification made to macOS, or perhaps an issue with the location of the .dmg file, then it is probably an issue with the .dmg file itself. Maybe it was corrupted in the download, or it was not properly created. If you have access to another Mac (especially an older version of macOS) to see if that .dmg file can be mounted as that may give us more information & clues.

Sounds like an issue with the .dmg file. First thing the software company should do is give you a verification hash code so you can verify the file you downloaded was not corrupted in the process. If the hash matches, then they should recreate the .dmg file so you can try the new one.

The software company should also verify that they can open the .dmg file on macOS Ventura on a different Mac than which created the .dmg file in the first place.

How did you acquire the .dmg file from them? I know that several years ago I had created a .dmg archive file which I tried sharing through Microsoft Sharepoint, and no one could open the file when downloaded through that method. Perhaps something similar is occurring with how they upload the file, or how the file is being downloaded.

I got the link (now deleted in this thread), thanks. But it needs creating a free account to download the demo etc. I'd rather not create unnecessary accounts, sorry. It is in the vendor's interest to make this work for their customers.

Are you able to open & mount other .dmg files you download? Such as from Vivaldi, or Firefox?

If you can open these files, then the issue is most likely with the developer of your app. If you can verify you can open & mount other downloaded .dmg files, then the developer should be looking at the issue with their .dmg file, by providing a hash verification code so you can be sure you are getting the file uncorrupted since the download process (or even upload process) can be corrupting it.

Edit: You can also perform a clean install of macOS and test whether you can open a new downloaded copy of the .dmg file. You can install macOS to an external drive if you want so as not to interfere with the setup on the internal drive. At least this will narrow down the problem.

All bets are off for managed systems especially when your user account is not even an admin account (mentioned at the very end of the EtreCheck report).

I can see a school putting in restrictions like this to help prevent people from running any unauthorized software even locally within their own user account.

You will definitely need to talk to the school's IT department regarding your needs for this software.

I was having the same issue on my M1 Mac Mini, but with downloading / using google chrome.

At first, Google Chrome stopped working, period. So I deleted it, and re-downloaded it. When opening up the installer package, I got the same error: "The disk image couldn't be opened. Failed to mount filesystems."

As stupid as it sounds.... restart your computer. It fixed the problem for me.

Is there a download link for the offending .dmg so we could test it?