The FileAPI accepts files with filenames that contain characters which are illegal in some operating systems. This can cause issues when those files are created in a OS where the filename is legal, then downloaded to one where they are illegal.
A student using MacOSX creates a file and saves it as
A teacher using Windows Vista opens assignment module and selects "Download all submissions". The submissionis not displayed because it contains illegal characters in its filename.
Clean filenames to strip characters / ? < > \ : * | " when a file is saved.