Source recorder error

When I try to play movies made with the Source recorder in Garry’s Mod it says it can’t find the sound file.
What would be the problem?

Are you activating any sort of custom sound during the game?.

I don’t think so.

Any console errors?

I figured it out. I was naming my demos “demo_name” and thought the command was “play”.
So it thought I was trying to play a sound file. Thanks anyway.