Password protected .dmg file does not open anymore after upgrading to Tahoe

After upgrading my MacBook pro 2019 to Tahoe, my password protected .dmg file (which contains my most confidential files) does not open anymore.


Luckily I stil have an old iMac running High Sierra, on this Mac I could still open the .dmg file and recover all my contents.


To be honest I consider this issue as a very poor attention to customers. New operating systems should NEVER prevent the users to access their files, moreover when they are encrypted.


If Apple engineers consider the old encryption weak, right implementation is to give the user a chance to open it and to convert it to a newer format.

MacBook Pro (2017 – 2020)

Posted on Oct 27, 2025 8:57 AM

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1 reply

Oct 27, 2025 9:20 AM in response to mcspada

I have seen at least one other report of this, though I have had no problems mounting encrypted .dmg files after upgrading to Tahoe (I have such files on my internal storage and on external SSDs). That makes me suspect the involvement of 3rd party software. That did turn out to be the case for a couple of users who relied on SSD manufacturer software (e.g., SanDisk, LaCie/Seagate) to encrypt their external SSDs.

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Password protected .dmg file does not open anymore after upgrading to Tahoe

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