Hello +Christopher Nielsen
What version of iTunes are you using? 12.2 or 12.3?
Are you using Windows 7, 8, or 10?
Please try this.
1. Please quit iTunes and the doubleTwist Sync application.https://www.doubletwist.com/help/question/guide-to-doubletwist-sync/#F
2. Search for all iTunes XML files on your system. The filename should be:
iTunes Music Library.xml
3. Please rename or remove all copies found.
* NOTE: Do not touch the "iTunes Library.itl" file as this is the actual iTunes library database. *
4. After renaming/removing the XML file, please launch iTunes. Go into the Preferences -> Advanced section. Make sure that "Share iTunes Library XML with other applications" is enabled. If it is enabled, try toggling it from on to off and then back to on to force the XML file to be created/updated.
5. A new "iTunes Music Library.xml" file should now be created.
6. Quit iTunes.
7. Launch the doubleTwist Sync application and you should get an alert that your iTunes is in a non-standard location and that iTunes will be launched.
8. Once iTunes has launched, the doubleTwist Sync application should then be able to detect the location of the XML file for importing.