I'm not sure if this is an appropriate forum or not (though it does apply to editing and modding), usually when you - by mistake or not - mix mod versions (client has one, server has another), FL will crash the client, the server, or both. Or, sometimes, like me, you'll get really odd results.

I recently completed a new RC Beta of 88 Flak, and hopped on the server, only to realize that I'm running RC76 and the server was running RC75. What I then witnessed is summed up in pictures here:
http://www.memes.no/88flak/forum/viewtopic.php?t=197
I'm going to warn you right now, that topic consists of 12 1280x960 screenshots. Make sure you won't tick someone off when your internet dies.

Everything shown in those shots were only what I was seeing - to everyone else, the game appeared normal. One thing that was interesting is certain ships like the Transport appeared to me as a Bretonia Battleship - upon ramming it, to others, it looked like I was bouncing off an invisible 'bubble' around the Transport.

So yeah. I just figured some of the modders here might get some amusement off of that. I personally like how FL stuck the Liberty Battleship engine on a Rogue Starflier (again, nothing in the screenshots was intentional - that's all FL being strange)