Like Joκκєrino said, take a look there, at RequestEnchantItem.java and look at isBlessed() or if(blessedScroll) method, depends of pack that you use and do the same, just change it to Crystal :P
Ex, on my pack blessed code looks like that
if (scrollTemplate.isBlessed())
{
// blessed enchant - clear enchant value
activeChar.sendPacket(SystemMessageId.BLESSED_ENCHANT_FAILED);
item.setEnchantLevel(0);
item.updateDatabase();
activeChar.sendPacket(EnchantResult.UNSUCCESS);
}
So, I have to change isBlessed to isCrystal, also I added a text message - sendMessage instead of sendPacket.
if (scrollTemplate.isCrystal())
{
// crystal enchant - clear enchant value
activeChar.sendMessage("Failed in Crystal Enchant. The enchant value of the item became 0.");
item.setEnchantLevel(0);
item.updateDatabase();
activeChar.sendPacket(EnchantResult.UNSUCCESS);
}
Btw, what pack are you using?