Error Mounting Disks After Enrollment

[landscaperose]

I'm encountering an issue with enrolling a users M2 MacBook Air. Following profile enrollment, I've hit a roadblock—I can't mount the disk, receiving an error message (-69842): "couldn't mount disk." Consequently, I'm unable to use Time Machine for backups as the drive isn't selectable.

Steps I've taken:

• Enrolling a different Jamf profile works fine.
• Backing up to an external drive using an unenrolled, fresh device also works fine.

While there are some policy differences, the setups are generally similar. What could be causing this discrepancy? I've tested the Jamf profile of this user on two separate MacBook Airs with different drives and both fail to mount disks after enrollment, ruling out a hardware issue.

Interestingly, the problem seems confined to this specific user—other user accounts function without any issues. Additionally, backups on their old Intel MacBook (currently enrolled in Jamf) work perfectly. Everything else with the new device is fine, it's just unable to mount external drives or do time machine backups. Is there a configuration setting or something else I am missing? Any insights or suggestions would be greatly appreciated!

[sdagley]

@landscaperose Do you have a Configuration Profile in scope for that Mac which has a Restrictions payload with Media restrictions enabled? That may prevent access to drives or disk images.

[landscaperose]

Thanks for replying @sdagley - the profile does not have any media restrictions. Also the user currently has an intel based MacBook Pro that is enrolled with the same profile and disk mounting/Time Machine work fine on that device. Again, when the M2 MacBook air is enrolled with the same profile as their current intel device, the device is unable to mount disks and Time Machine does not work.

[sdagley]

@landscaperose Enrolling a Mac for the same user does not necessarily mean the same Configuration Profiles will be applied to both Macs. I'd suggest you check all of the Profiles installed on the M2 Mac (System Settings->Privacy & Security->Profiles) to see if they include any restrictions.

[landscaperose]

Hi @sdagley I double checked there is nothing listed under Media Restrictions. The only restrictions I see are related to iCloud, AirDrop, and Game Center.

[sdagley]

Do you have any security software installed that may impose device restrictions?

[landscaperose]

I checked the security software event logs and it sees the drive and is allowing it.

Something else to note that may be a clue is the permissions for the external drive are stuck at Read Only Access Permission. I've tried to change the permission by mounting the disk and changing permissions in terminal but it isn't changing.

[landscaperose]

However, the Volume I made for the backup has Read Write Execute permissions.

[sdagley]

Do you have an another external drive you can try to see if Read Only is being applied to just that specific drive or if it's any USB device?

[landscaperose]

I've tried with multiple USB devices and gotten the same error. The drives work on the Mac when it's enrolled with other users profiles. I've also tried to do this in safe mode with no success.

Unfortunately this seems like it is specific to this one users jamf profile. Everything else works fine, just not disk mounting and thus Time Machine Backups.