Can't unlock folder on Mac HD Ventura

Your original screenshot of the Get Info window shows "Fetching..." for the owner's "name" field which tells me there is some problem here causing macOS to take way to long to get the permissions information or is unable to retrieve it. If macOS is unable to retrieve the owner's permissions, then it makes sense you won't be able to do anything with that item. Maybe try changing the item's permissions...may require use of the command line.

When you run First Aid, make sure to run First Aid on the hidden Container. Within Disk Utility you may need to click "View" and select "Show All Devices" so that the hidden Container appears on the left pane of Disk Utility. Even if First Aid says everything is "Ok", click "Show Details" and scroll back through the report to see if any unfixed errors are listed. If there are any unfixed errors listed, then run First Aid from Internet Recovery Mode, otherwise you will need to perform a clean install of macOS by first erasing the drive followed by installing macOS & restoring from backup.

I've never locked a macOS folder before so I don't know exactly how macOS does it. If changing permissions of the folder doesn't help, then you may be able to remove it by using the command line which may ignore any higher macOS attributes associated with the file.

You may want to check the folder permissions using the command line. Start by typing the following, make sure to leave at least one space after the last character. Using the Finder, drag & drop the folder onto the open Terminal window to auto fill the path to the folder. Then press the "Return" key to execute the command. Take a screenshot of the output of the command for the line with the folder and any lines after it until another line with the next file/folder is listed.

ls  -hle  

I know the other contributors here are much more familiar with macOS permissions (especially ACLs than I am).

I recently had to temporarily disable SIP before I could trash a remnant folder of a macOS installer package.

System Report... > Software > System Integrity Protection: Enabled/Disabled.

Command-R boot into Recovery partition to change. Rather than booting into Recovery Mode again to turn SIP back on, you can just run the command csrutil clear, and SIP will be reset to enabled.

csrutil status

If SIP is on – “System Integrity Protection status: enabled.”

If SIP is off – “System Integrity Protection status: disabled.”

csrutil disable

csrutil enable

csrutil clear

p.s. Is there something special that might prevent trashing inside the offending folder?

Configuring System Integrity Protection

APPLEAL wrote:

I cannot unlock a folder in my documents folder. I have a copy of the data. The checkmark next to lock is greyed out.

When I try to trash the folder I get "The operation can't be completed because the item "XXX" is locked.

FWIW, this is an admin acct.

I ran Disk utility - First Aid and safe boot...no luck

How to get rid of folder?

Thanks for the help

This is what the permissions show:

https://discussions.apple.com/content/attachment/8d707dfe-4e70-45ed-b6f2-b21c46d7901a

You can try again from a Safeboot and compare your results

A SafeBoot How to use safe mode on your Mac - Apple Support will sort many anomalies

Is this sync with iCloud or /external drive/ local only...(?)

ref: unlocking a folder - Apple Community

ref:

Lock a document on Mac - Apple Support

Is the disk image unmounted? I guess it should be after all the restarts.

Could you copy the .dmg elsewhere, and verify that it opens OK. And then try to nuke the offending folder or the enclosed .dmg with more ammo.