You may have run into this behavior due to the latest file system change.
Did you use to have Logic Pro 9 installed on this computer/system?
Read the article first:
Try this if you recognize that your Audio Music Apps folder is an orphaned alias:
- Quit Logic Pro X.
- Delete the Alias ~/Music/Audio Music Apps then create a new folder on this location and give it the name Audio Music Apps.
- Open the Terminal and paste this code followed by enter:
open /.HFS+\ Private\ Directory\ Data?/
- A new Finder window will reveal your hidden content.
- Copy the content inside the 'dir_######' folder and paste it inside your new Audio Music Apps folder.
- Relaunch Logic Pro X.