Hi Ernie,
I've found a compatibility issue probably with your app server and TTS. I am studying Japanese, with sound files from TTS. The filenames would then be
unicode Japanese characters. When I export the file through your server, it seems that the server doesn't accept unicode japanese characters under the "Sound 1", "Sound 2"... column. Thus sends a warning message "Export Error: Picture/Sound file must be contain only the following characters a-z 0-9......"
I've also tried merely upload a flashcard with unicode characters under the "Sound" columns, which doesn't work.
Exporting to Dropbox works. FYI, I've also tried exporting to Dropbox with the media files, all works perfectly.
Thanks,
jason