Problem Solved

Today I managed to render the scene that was not working. This was done by rendering the scene on Final Cut Pro rather than on Adobe After Effects. This means that all the scenes that I need for the film have been rendered and put together in Final Cut Pro. Also, because one of my scenes has a shell exploding in it, I needed to have the screeching sound of the shell as it hurtled towards the ground, yet unfortunately there were no sound effects that included the screeching. However, I simply found a sound effect for a kettle boiling (whistling) and took the whistling noise and put it in before the explosion of the shell. By doing this, I have acheived the sound that I was looking for.