I have a Cakewalk project that suddenly gives me a popping noise followed by silence. When this happens the Mix bus and Master bus both show the meters going into red. I've found that if I disable the effects from the Mix bus then enable them again the project usually goes back to normal. This also happens if I delete a track from the project...when that happens I have to close the project and reopen it to get it work again.  I tried creating a new bus to replace the mix bus... that didn't help.