Hmmm...........
Where did you get the 256Gb Flash Thumb Drive?
There has been some HACKED Thumb Drives being sold as 256Gb or 1Tb.
When you plug them in to a USB Port, Windows will report that it is 256Gb or 1Tb.
But when you check their actual storage capacity,
they check out as only 8Gb or 16Gb of storage space.
Here's a site that has links for free Flash Drive Tools.
https://www.raymond.cc/blog/how-to-c...b-flash-drive/
Another thing.........
If it is always stopping at one particular file, on the drive your trying to copy.
Then that file has been so badly corrupted, that it is no longer viewable by the Operating System.
You will need to get a recovery program that can restore the file.
Well, good luck with it.
Signed: Ensign Tzap