File permissions don’t allow the current operation
Copy the displayed error message and contact your server administrator or server hosting provider for assistance. Include the text of the error message, as it may assist the person handling the help request.
The directory is protected
Check the directory that you’re trying to transfer files to. Is it protected, or a system directory? Try transfering a file to a different directory.
The file is open in another program
Windows machines tend to lock files that are currently being used by an application. While the file is locked, FileZilla/FileZilla Pro won’t be able to transfer it. Try again when the file is not open in another application.