"initialize the output module 'MP4' failed" happened usually because you do not have the privilege to write anything into the destination drive.
If you used an external drive as destination, please make sure the connection is OK and you can try other USB port, if the above is ok, please re-make the selection to the usb drive as the destination.
If you used a network drive as destination, please make sure you have the privilege to write data, and you can try to map network drive: open a folder on your computer, then click "Tools"->"Map Network Drive...", then find your network drive by Browse... button beside Folder:, then check "Reconnect at logon", then click "Finish" button to save. Then choose the mapped drive as destination.(or if you already mapped the network drive, you could try to re-map it.)
If you used a general internal drive as destination, please check and correct the writing privilege, or choose other drive as destination.
Any problem, please just contact firstname.lastname@example.org .