Solved Unfamiliar error with chkdsk

I'm having problems scanning a flash drive that holds an important image file. The error reads "A snapshot error occurred while scanning this drive. You can try again but if this error persists run an offline scan and fix."

How?

Looks like a USB problem on my PC - the one I've just upgraded from W10 to W11. By plugging the flash drive into my laptop I've been able to copy the image file to the laptop and verify it. PC probably needs some new drivers - if available! If not I may have to roll back to Win 10 - using the image i just saved! Classic example of what a life saver Macrium Reflect can be.