I've had issues with them before. But I determined that I'd actually saved a couple of them in my template. I built a new template and the problem seemed fixed. But today, I actually witness a "group of tracks die!"

I was processing an audio file with a plug in. For some reason, when I hit preview, the plugin crashed and told me to re-install it, which I did. But the crash required me to restart my controllers, as SOME functions stopped operating, and, on playback I realized that 5 tracks directly after the crashed track had "died" no VU/LED activity. I replaced all of those tracks with the fix I described and they are all playing correctly now. But I'm wondering what causes this.
Has anybody else had this happen?