Hi: In Witcher I, I'm in chapter 3 and suddenly I cannot make the Swallow potion. I have made many of the potions in earlier chapters but suddenly I can't make them any more. What is happening is that there are only 3 slots shown for mixing potions. The swallow potion requires 4 slots. Cant find any potion that is available that shows 4 slots, all potions are limited to three slots. Any suggestions??