Did you check all the things that you replaced? It might also help if you remove the MotionEtc archives as well.
Ok, I'll try that.
Get a fresh one and add just one texture to it, then enter the CSS. If it doesn't freeze, keep adding all your textures back until you encounter your first freeze. At that point, start removing textures until you don't freeze again.
Also, I had a problem recently whenever I added CSP text my game crashed upon entering the CSS. This was a problem in BrawlBox ModSet 4.1, so if you use that version of BrawlBox and are adding CSP text, that could possibly be what the problem is. But if you're not adding text or not using that version, just get a fresh common5.pac and do what I said and see if that works.
I've tried it with each. THe color specific image of the character in the Css crashes. So does the text. Also I have tried the character icon (Below the Text). All on a fresh one. I've only tested Text with the last one from Kyral. I've only tried The large portrait in 4.1.