I've run into a strange bug in the film viewer. The engine sounds do not work if the film starts with the engine already running. I can hear other planes engines, and all other sounds work (flaps, stall horn, guns, etc). If the engine is turned off and restarted then the engine sounds return to normal. The weirdest part is this is only happening on one of my films, all others still work properly. Not sure if it's a sound file issue with a specific plane but I'll try testing that out today.
Attached is the film I'm having issues with. For the entire first half of the film there is silence coming from the 152's engine, but when he shuts down the engine and restarts is the sound comes back. This didn't always happen either. I've been working on this film for a little bit now with the engine sounds working properly, then it just stopped working yesterday.
Quick test in offline shows that Ta152 sounds work both from engine startup and having the engine running from the start of the film.