If the launcher is not working, please first check that you have working internet connection, firewall is not blocking Launcher's access to internet.
To fix this problem for Windows computers, please follow these instructions:
Delete folder: C:\users\username\AppData\Roaming\Yousician Launcher\Yousician.app\ (the folder directory may vary depending on your Windows username.)
AppData folder might be hidden so you might need to do this:
Then run the Yousician Launcher.exe again, it should download the app and start running it correctly.
Also Yousician might not start properly if you are running Windows 7 or Windows 8 and have not installed the latest OS updates. Read here how to fix that.
Mac OS X
Check Yousician system requirements.
If you are still experiencing trouble with the launcher please submit a request.