Since the update to 7.0.3, the Media Uploader addon does not allow any user to upload a file with the m4a extension. Upon attempting to do so, I get the default "Not allowed file type" message.
I have tried disabling my caching plugin, enabling and disabling all file extensions listed (followed by save & refresh), as well as disabling & enabling the plugin altogether, but the error persists.
Audio files of mp3 extension upload without a problem, but m4a files do not. What can I do to get this working again?