Macintosh HD — Data” can‘t be unlocked.

You should reply to the original message that deserg posted.

Why are you asking?

Did you reinstall the OS and now are getting a message about not being able to unlock Macintosh HD - Data?

That might be because you didn't remove the old Data volume when you reinstalled.

If you open Disk Utility, do you see more than one - Data volume?

Then what should I do to solve the issue?

I'm not sure without more information. that's why I hunted down the message you referred and tried to post a link to it, but I failed.

I did see more than one Data volume.

Do you still have access to all of your files?

If so, you can just remove the orphaned Data volume.

In Disk Utility, select each - Data volume and look at the Mount Point in the info pane.

If the Mount Point is at /Volumes, you can click the Remove Volume button ( – ).

The - Data volume mounted at /System/Volumes/Data is the current Data volume.

Here is a link to the original message: Mac models with the Apple T2 Security Chip - Apple Support