I’m not personally familiar with Synology’s products, but if what’s going on is that you’re using some built-in feature of a Synology NAS to copy files from a USB drive to the NAS and seeing an error, I’d probably try copying that particular file to somewhere else on a PC, cutting the NAS out of the loop, to make sure that you don’t have, say, a corrupt filesystem where attempts to read the file contents are failing.