Why am I getting this message when hitting the space bar during editing "No Valid audio output channels for playback found. Please check the audio hardware preferences." please help i've really hard on this project and now it wont let me complete it because of this message.
As I interpret that this error appeared after an edit time, in that case I recommend, if appropriate, uninstall any plugin that has installed the program, and try.
Have you checked the Audio Hardware preferences?