The problem is Final Cut Pro X.

Final Cut Pro X clearly isn’t meant to be a professional video editing program… I mean, who offers software that doesn’t export a file type to be used for the next link in the chain?! i.e. Post-Sound

Only Apple designs software with intended limitations, so you have to spend more money on “third-party” apps…

Also, MadOpus, I believe if you have all the files in one folder from the editor, or client, for X2Pro to reference, it will work on your system as well. Don’t quote me, as I haven’t had to use it. All the editors I work with are using professional programs to edit in. ;)

Sound4Picture about X2ProLE Audio Convert