Can't Embed Flv (flash Video). All I Get Is Blank White Space.

I have a phpBB (3.0.x) forum and it's got this mod installed called Advanced BBCode Box 3 and I can't get the FLV BBcode to work. Every time I try embedding a video with it, all I get is nothing (Firefox) or a blank white space (Chrome). I've tried embedding from four different sites now with no luck. I'm guessing if it doesn't matter which site I embed from, then it must be an encoding issue. Can anyone tell me how to properly encode flv videos to avoid getting a blank white space?

 

You're best option is to visit the support forum of the software you are using for your forum.
There are various forum softwares and they all have there own way of using BB Codes.

 

It was my fault. I'd somehow deleted flashplayer.swf without realizing. I uninstalled and reinstalled Advanced BBCode Box 3 and everything's back to normal now.