Big Sur fails to mount encrypted volume

Question

Created Jan ’21

Replies 4

Boosts 0

Views 3.8k

Participants 3

I have a problem mounting an encrypted volume on Big Sur (11.1).
In DiskUtility, when I select the volume, click Mount, enter password and click Unlock, nothing happens.
I also tried to use CLI to unlock the volume using command:

Code Block diskutil apfs unlockVolume /dev/disk1s6

but it gives me error:

Passphrase:
ACM: LibCall_ACMContextCreate: returning, err = -536870181.
Error -536870181 (0xe00002db) creating ACM Context for passphrase

I also tried to create a new encrypted volume with simple password '123', but after I unmounted it and tried to mount again I got the same error.

Device: MacBook Pro (16-inch, 2019)

Is it a bug in Big Sur or am I doing something wrong? Should I just wait for an update with a fix?

I don't have an urgent need to decrypt the data because I have a backup. The question is about possibility of using encrypted volumes in macOS.

Answered by qnox81 in 655819022

I contacted support today with this issue and after few ideas they asked me, if I can access FileVault in preference and unlock it - I Was unable to do so - my password looked invalid.

Then they asked me to perform SMC reset and after that I was able to unlock FileVault and all my encrypted volumes mounted OK.

Now everything with encrypted APFS+ volumes works OK.

Boost

Answer 1

qnox81 OP

Jan ’21

Got the same issue with external drive on MacBook Pro (15-inch, 2019). Pretty sure got correct password for encrypted volume, but cannot mount it.

Any Ideas?

0

Answer 2

qnox81 OP

Jan ’21

Accepted Answer

I contacted support today with this issue and after few ideas they asked me, if I can access FileVault in preference and unlock it - I Was unable to do so - my password looked invalid.

Then they asked me to perform SMC reset and after that I was able to unlock FileVault and all my encrypted volumes mounted OK.

Now everything with encrypted APFS+ volumes works OK.

0

Answer 3

-ihor- OP

Jan ’21

I did these steps from the article and it works now. https://support.apple.com/en-us/HT201295

Before resetting the SMC, try these steps:
Shut down your Mac.
Press and hold the power button for 10 seconds, then release the button.
Wait a few seconds, then press the power button to turn on your Mac.

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Answer 4

mgluby OP

Jun ’22

With new MacBook Pro, when I leave the device overnight and then try to login to encrypted volume, it consistently silently fails. Rebooting device makes it consistently works. It seems when device goes to sleep, it no longer is in a state where it can open encrypted volumes (I only use encrypted volumes, I don't know behavior for unencrypted volumes).

This has been consistent behavior for many months with new MacBook Pro (never happened on my older Macbook Pro).

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