Can't create image from USB using disk utility

I did a search before I posted this question but I guess I did not search well enough.

After another hour of combing through questions I found the answer.

Prefs -> Security & Privacy -> Privacy tab

Select Full Disk Access in the left pane

Click on the lock at the bottom left of the screen

Enter your password

Then, press the + button near the center of the screen

Add Disk Utility to the list

Click on the lock at the bottom left of the screen to lock out further changes

Now it works.

Found it.

Disk Utility needs full disk access, which I guess is not allowed by default.

Might I suggest that rather than making images of these flash drives, just save the macOS installer app from which the flash drives were made. In my situation, that is what I do.

A great suggestion and it would work perfectly, but as you went on to point out, it doesn't fix the overall issue of the imaging tool not working.

Frankly, based on what you have posted, I have no idea why it doesn't work unless there is something else at play.

I agree, there is some fundamental issue that is causing this. I'm hoping someone else has had and resolved this issue before.

When you selected the menu option to make a new image from the disk, do you recall what the default options were? On my system they were: read-only and None.

Yes, mine are the same and it saves to documents as a default.

I wonder if there isn't something on the USB flash drives that is preventing the process from working. You might run Get Info on them to check the permissions. Mine shows: Owner is "...(Me)" with r/w; Group is "staff" with r/w; and Everyone is "Read only". At the very bottom the Ignore ownership on this volume options is checked.

Mine is the same for all of them. I suspected they might be the issue. So, I took a brand new flash drive straight from the package and copied a file onto it. Then, I tried to image it and ran into the same issue exactly. So I erased it and partitioned it to default values, exFAT for a 32gb drive. Again, I tried to image it and again I had the exact same issue. Each of the four drives are made by different manufacturers.

I believe it's fair to say that I have eliminated the drives as an issue. I have also tried all of the drives on each of the usb ports on the computer and the issue persists.

It is very frustrating.

Again, thank you for taking the time to reply.

Why do you need them to be backed up as images? You cannot boot from a disk image.

I need to have a backup of these dives in case they are lost or damaged, and I'll need to be able to restore them to other drives if either of those happens.

A progress window should open.

It does not. The drive unmounts, and disappears from the desktop. Then it immediately reappears and the creating image dialog says "Operation canceled" as I detailed in my original post.

does the progress window provide an error message

No, unfortunately, it just says operation canceled.

Have you sufficient free space on the internal drive to save the image?

Yes, almost a TB of free space

Do you have any other problems saving files in your Home folder?

No, downloads, and textEdit have no issues saving files to the home folder

This works just fine on my system running Catalina.

I know. That's the frustrating part. I've done this before on other macs without issue. I imagine that I have a software configuration issue that hasn't been isolated yet.

Thank you for taking the time to reply.