macos – “Untitled” can’t be opened because the original item can’t be found

Yikes! It’s scary to possibly lose data. I’ve been in this situation and may be able to help.

In this case, the reported error message is a permissions issue.
I know of two things you can try in order to override permissions on this volume.

Option 1: Disable Permissions:

Use “Get Info” on the troubled drive (in this case “Untitled”) to enable “Ignore ownership on this volume”.
This is a temporary change and is reversible. Requires unlocking first.
More Detailed instructions from Apple are here.

Example screenshot:

Option 2: Write Over the Permissions:

Caution: Proceed with care. If you don’t know what you’re doing, don’t try this on a bootable volume.

You can change the permissions to “Read & Write for everyone” and apply those settings to all enclosed items using Get-Info or with the CHMOD command via the terminal.
More detailed Instructions are clearly written up on HowToGeek here.