APFS Encrypted SSD error message

I recently reformatted two Samsung T7 1TB SSDs to APFS Encrypted (Sonoma 14.3.1) and backed up my internal drive to them using SuperDuper Smart Update.

The drives, which contain data only and are therefore not bootable, mount fine, but in Disk Utility, if I unmount the Container of either one and later mount it, the drive reappears on the Desktop with this error message:

“Could not mount ‘AppleAPFSMedia’. (com.apple.DiskManagement.disenter error 49229.)”

This does not occur with an identical T7 SSD that is unencrypted.

Should I just ignore the message?

My only concern is whether I will later have a problem using Migration Assistant after a system upgrade.

Thank you,


Don’t mount the container. Mount the volume inside the container.

Thanks for the suggestion, Michael. That works fine, but my question now is, why should there have been an error message? (I was able to dismiss the message and the volume apparently mounted with no problem.) In some cases I would like to mount all the volumes in a container, so mounting the container is more convenient.

EDIT: Note that I have only had the error message with the encrypted drive, not the identical unencrypted one.

I’m not really sure. Do a diskutil apfs list and see what volumes are in the container.

I think it means that there’s another volume in the container that it doesn’t want to mount. So the message is in relation to the unmountable volume, not the one it did mount.

There may also be relevant messages in the Console but good luck finding them.

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