Try the below steps and check to see if it helps
Open Folder Options > Control Panel > Classic View - Small Icons > Folder Options > Select View tab > Make sure that Show hidden files option is checked. Also uncheck Hide protected System files.
Re-insert Flash drive to see if you able to view your files. If yes copy the important files to your Hard Disk > Change the attributes that the files can be read ( Uncheck Hidden / Archive option) > Format your Flash drive after making sure you grabbed all important files. Re-copy the files that you had already.
Now the files will be visible in all machines and even though Show Hidden files options is Unchecked.
Hey can you provide any error snap for the same???