Sound Card error

Hi! I'm pretty new to FL and new to music production. That being said, I was wondering if its possible to use FL without my sound card plugged in? Because I'd like to be able to edit some stuff whilst just laying in bed or when I'm traveling, but having my sound card plugged in makes it a little bit akward. Everytime i open a projekt without the sound card I get the error message "not enough asio output channels available" and nothing in that projekt showes up. Is there a way to fix this or do I just have to always have my sound card plugged in?