after effects audio plays for a few seconds then stops

i need some help please.

every few months i would make an edit just for fun and recently i started one but i had a problem with audio. i would press play on the timeline and it would only play about 1 second of the audio and then stop, but the timeline marker would carry on playing. the same thing would happen if i moved the marker over a little bit so i was at a different point in the song. 

i opened some of my old project files, and they all worked perfectly, its only the new projects that i create that face this problem with the audio preview. 

any help at all would be appreciated but i want to clarify first of all that i know its not the cause of low storage as i've recently uninstalled about 100gb of games to see if that would help, but it didnt. 

thanks guys!