the only way to know for sure if it is a problem with the style is to switch over to prosilver and see if it works there.
most likely it is a problem with the youtube bbcode itself.
there are some older bbcodes for youtube that are no longer viable, there was some significant changes to the way bbcode work in 3.2 etc.
have to figure out which is causing the problem.
try the prosilver first. if that doesn't work then show us the exact bbcode and html replacement that you are using for youtube.
I'm baaaaaccckkkk. still doing work on donation basis. PM your needs.
Premium phpBB 3.3 Styles
I am pleased to announce that I have completed the first item on my bucket list. I have the bucket.