Error with source recorder. Help?

Well, I was filming another short skit for a gmod movie using source recorder, and I set up the scene and then positioned the gmod camera as per usual. The filming went perfectly , but when I went to play it back, the camera had stop working and the scene was being viewed through my player’s eyes. I checked the console to see what was wrong, and I saw this:

entities/gmod_cameraprop/init.lua:128: Tried to use a NULL entity!

What happened and how do I fix this? Please help. :S

You have to place any cameras after you start recording.

Really? Oh, that sucks… The camera I needed to use is attached to a contraption which i built to move the camera around, and it took me a while to build, so do I have to film my self building it again?

Or you could use this:

Doesnt take almost any time and its alot better than contraptions.

I’ve finished my film…
Anyone wanna see it?

Thanks but no thanks.