Not able to mount DMG or external storage after upgrade to 12.4 update?

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Not able to mount DMG or external storage after upgrade to 12.4 update?

I wonder if someone has some advice on how to solve my problem. I am not able to mount DMGs or external storage devices anymore after the upgrade to 12.4 last week. If I connect the device (USB disk for example) and reboot, then it will mount. However if I try during the system running then it won't mount the final step. It will appear in the disk manager, but the mount produces such an error as seen in the attached screenshots. I am able to run first aid on the attached disk and that runs without issues and finds no faults.

In safe mode, I am able to attach and read devices without issues. I have formated my disk and restored it from a cloned backup of my system, which hasn't helped. Diffrenent file systems don't seem to matter either, its the same problem.

The fault as you see says:

Could not mount "Sandisk". (com.apple.DiskManagement.dis enter error-119930876.)

Trying to mount from the terminal hasn't helped.

Mac mini, macOS 12.4

Posted on May 23, 2022 11:42 AM

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Answer 1

Top-ranking reply

steve626

Level 6

15,819 points

May 23, 2022 5:37 PM in response to telegix

telegix wrote:

In safe mode, I am able to attach and read devices without issues.

As tbirdvet points, this indicates that something installed is conflicting.

To find out what it is, download and run Etrecheck and post the results here using the Additional text button below. You can inspect what you are posting, it is anonymous technical info about your computer and what is installed, nothing else. This may reveal the cause of the problem.

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Answer 2

tbirdvet

Level 6

17,669 points

May 23, 2022 11:52 AM in response to telegix

This may not help but try SMC and NVRM reset. Are you using any software that came with the SSD? That may cause an issue.

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Answer 3

tbirdvet

Level 6

17,669 points

May 23, 2022 4:42 PM in response to telegix

I do not have 12.4 (still on 12.3.1). The fact that all is OK in safe mode could indicate that there is some other file or driver causing the issue in normal mode as Safe mode bypasses all those. Not sure what that would be however. Do you have any other drives that are not Sandisk to try?

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Answer 4

tbirdvet

Level 6

17,669 points

May 24, 2022 6:25 AM in response to telegix

You need to format the SSD to APFS GUID Partition. That is what Monterey works best with.

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Answer 5

telegix Author

Level 1

8 points

May 24, 2022 1:30 AM in response to steve626

I agree it must be something conflicting with the mounting process, but only after the upgrade to 12.4. I have tried all kinds of various storage types, it's not a specific device..! Even a downloaded DMG doesn't mount at all... Output from EtreCheck is attached as additional text..

EtreCheck

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Answer 6

telegix Author

Level 1

8 points

May 24, 2022 2:06 AM in response to steve626

I tried also, sticking a USB memory stick which then mounts during bootime fine. I went into disk util and formated the volume this time to the old mac file system... It does format and then can't mount it after:

Erasing "SanDisk Ultra USB 3.0 Media" (disk2) and creating "Mac OS Extended"

Unmounting disk

Creating the partition map

Waiting for partitions to activate

Formatting disk2s2 as Mac OS Extended (Journaled) with name Mac OS Extended

Initialized /dev/rdisk2s2 as a 57 GB case-insensitive HFS Plus volume with a 8192k journal

Mounting disk

Could not mount disk2s2 after erase

Operation successful.

Tried the same with exFAT also on another stick:

Erasing "SanDisk Ultra Fit Media" (disk3) and creating "exFAT"

Unmounting disk

Creating the partition map

Waiting for partitions to activate

Formatting disk3s2 as ExFAT with name exFAT

Volume name exFAT

Partition offset : 411648 sectors (210763776 bytes)

Volume size 242200576 sectors (124006694912 bytes)

Bytes per sector : 512

Bytes per cluster: 131072

FAT offset 2048 sectors (1048576 bytes)

# FAT sectors 8192

Number of FATs

Cluster offset 10240 sectors (5242880 bytes)

# Clusters : 946056

Volume Serial # 628c9ca5

Bitmap start : 2

Bitmap file size : 118257

Upcase start : 3

Upcase file size : 5836

Root start : 4

Mounting disk

Could not mount disk3s2 after erase

Operation successful.

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Answer 7

telegix Author

Level 1

8 points

May 24, 2022 6:54 AM in response to tbirdvet

I know that of course and the large SSD is indeed APFS format.. I was testing other disk formats on the memory stick to see if its an APFS issue or not.. See my screenshot, you'll see the sandisk extreme is APFS...

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Answer 8

telegix Author

Level 1

8 points

May 24, 2022 7:20 AM in response to tbirdvet

No app or almost no app can upgrade itself which downloads a DMG from the internet and updates like that also. Or if download a normal DMG and try to copy files from it.

Honestly, the focus is not with type of disk, or type of formating. There is something getting in the way of the final mounting. I have no virus or such program installed also.

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Answer 9

telegix Author

Level 1

8 points

May 23, 2022 12:21 PM in response to tbirdvet

I will try that, good advice... I am not using any software which came with the SSD. I went and straight formated to APFS after buying it.

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Answer 10

telegix Author

Level 1

8 points

May 23, 2022 12:31 PM in response to tbirdvet

Ok, I just did the SMC and NVRAM and didn't help.

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Answer 11

tbirdvet

Level 6

17,669 points

May 24, 2022 8:30 AM in response to telegix

As a test I updated one of my Macs to 12.4 but saw no issues. All my external drives mount as expected so still do not understand what is causing your issue. Perhaps another user will help out.

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Answer 12

telegix Author

Level 1

8 points

May 24, 2022 9:00 AM in response to tbirdvet

Yup, my MacBook air M1 has no issues at all with the same drives.. :)

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Not able to mount DMG or external storage after upgrade to 12.4 update?

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