Often, these messages appear as a video, rather than as a player error message. Your player will not name a specific program required to view the movie; it would likely say something like "missing CODEC" and offer to search the web for it. Of course, with VLC, that's unlikely to happen.

There are a few scams using this technique. One of them is DOM player. Never install any of those players as each is a trojan.

If you check each file via the link to Bitzi, you can escape these scams, along with mis-named or poorly-recorded files. Before downloading, right-click on a movie in your search window, go to Advanced, select Look up file using Bitzi (or something very similar). Your browser will open at the Bitzi site, and show you info re the specific file you selected.

I'm going to have milk and cookies now. After you've tried Bitzi, you'll want me to have milk and cookies!