More information would be helpful.
What are you trying to copy is it a dvd or a film on your hard drive.
What spec of computer do you have.
How much free space on your hard drive
How much memory
What operating system
What software are you using to copy the movie
Probably it's needs some file space to do the rendering and is telling you that there is not enough room on the disk and asking you for another path (to another disk) where it can store the temp file.
"or something about another path...."
It always amazes me that the number of people who ask for help but just can't be bothered to give simple information like exactly what messages they are getting.