When your subscription expires, you won't be able anymore to open your parts if the total number exceeds 15.
But not to worry! Your parts are still saved in the Newzik Cloud.
To access your music, you have several options:
1. Delete some parts to go below the 15 parts limitation
2. Export your parts outside Newzik as PDF files
3. Subscribe again to Newzik Pro, or purchase the Lifetime licence