Team Fortress 2 Demo: Unknown command “demopauseafterinit”

Sometimes this error can pop up due to a corrupt file, or changes in the TF2 version. If you know that isn’t the case (the TF2 version is the same, etc), it is possible that the Demo Editor is causing problems.

Delete the .vdm files in the same folder as your demo. You’ll lose your edits, but the video will be playable again.