Exporting world produces empty (0KB) file.

Every time I try to export my world and save it to a folder, it says level export finished successfully, but as soon as I go onto the file I saved it on, it says 0KB. How do I fix this? I want to be able to save my world as a backup in case it gets corrupted. I have tried to sasve to other folders, but no luck. My Hardcore world is 197.1MB.