I just finished rendering a video to find that none of my fancy Sapphire-based transitions rendered properly (despite the preview being fine). To say I'm incensed would be an understatement. >.>

Is there some wonderful tech wizard on here who could tell me what happened? 

Ah that's unfortunate :/
I think I had that one time happening and had to re-do every transition which used the Sapphire plugin, what type of transition is it? The hyper zoom type of transition? Or is it a variety of transitions?

@ZAFuzzy BOOST A variety really. Not sure how to describe it, they were 3rd party transition packs which USED the Sapphire plugins. Sort of like fish eye, slide in/out, zoom in/out, with blur effects added. The kind of deal you find on documentary YT videos.

@Death in Heels woah! Sounds like you having a ton of fun editing videos
Do you make use of the Magic Bullets plugin too?

This might or might not work, but what I do is to get the Sapphire plugins always to work, I unbind the video from the audio, I split the the first video clip at the end (from the end part of the clip, 7 frames, split) and I do the same with the second video clip, but on the first 7 frames, I make the 2 clips fade into each other with 1 frames each (2 frames in total) and then I add the Sapphire transition that I need, I mostly do the hyper zoom for Sapphire

@ZAFuzzy BOOST When it comes out well, sure
I've never heard of Magic Bullets, I'll have to take a look!

Aw, you're kidding me. I thank you for the advice but what a pain in the plumbum. >.>

@Death in Heels Oh it's a real pain in the, like you said, plumbum (made me lol) but I think that does the trick to get it to work all the time for me, might work for you too