In order to remove Yousician cache files on your Mac machine please follow the steps below:
1. Open a Finder window:
2.In the Finder, click the Go menu in the menu bar:
3. Select Go to Folder in the Go menu:
Type in ~/Library/Caches and hit enter to proceed to this folder:
If the "Caches" folder is open jump to the step 4.
Alternatively after clicking the "Go" menu when you see the drop down hold the "alt" or "option" key:
The library folder will be shown in the drop down, click on it:
The library folder will open in a new window, find a folder named "Caches":
4. In the "Caches" folder you need to delete the folder named unity.Yousician.Yousician:
5. Go back to the root of the Library folder and then choose "Preferences" folder in Library:
7. Delete the file unity.Yousician.Yousician.plist:
8. Reboot your machine.
9. Launch/install Yousician again.