Explain the issue you are having:
Trying to add a song to a collection when the host changes the mapset to a song you don't have displays the an Error somewhere in osu! message. If you click add mapset again, the game will crash with a Null reference error.
Trying to add a song to a collection when the host changes the mapset to a song you don't have displays the an Error somewhere in osu! message. If you click add mapset again, the game will crash with a Null reference error.