Please confirm the information below first.
1. Make sure the iTunes version is 188.8.131.52 or later.
2. Make sure you checked Share iTunes Library XML with other applicationsin iTunes Preferences>Advanced.
3. Make sure the M4V videos you want to convert are downloaded to local hard drive.
If it still does not work, click top Settings>Help>Bug Report, submit Bug Report.
This FAQ is about: Frequently Asked Questions, TunesCopy, TunesCopy for Mac