conversion zulu script 095 to 97 . Spells anim(FX) problem

[Nightmare]

we have this problem ... we use mondains legacy (client version 6.0.1.6) and pol 097 coregina. When we cast spell some of that doesn't work. the graphic of spell don't show and the client crash.. We have looked in the client.inc file and the spells FX id are correct. What's the problem ? it's not playable because if a pg or npc cast one of that spell the client crash

Second question : i want to change the original spell graphic (fx) whit a new beautiful anim of spells ... so i've created some new item whit animation (beautiful spells) for kal vas flam healing ecc... so i changed the fx id in the client.inc file. We compiled it and upped in the server but doesn't work ... The kal vas flam ? it's the original and not the new graphics
Why ?
Please help