1. Wireless network connection problem: If you connect the car music system through a wireless network, you may not be able to open it because of unstable network connection or weak signal.

2. Car phone problem: If the car phone interferes with the music system, the music system may not work normally.

3. Server problem: The music system may rely on cloud services to play music. If the server is out of order or under maintenance, the music system may not open.

4. Software problems: There may be some bugs in the music system, and the software version is not up-to-date, which will also make it unusable.

If such problems occur, it is recommended to try to restart the vehicle, check the network connection, ensure that the car phone is turned off, update the software version and contact the dealer for help.