I tried mixing the "KNIGHTYME PLEASURE" spell, and added all correct ingredients. I had 1 feather, 5 beetles and 2 Deadly Nightshade (I had 10 in total but you can add only all 10). Elvira says that they are the wrong ingredients. Is this a bug?

Okay I posted too soon. I was adding the beetles from my backpack instead of the normal inventory where the bugs would be stacked. The game didnt like that and thought I did the recepie wrong. Make sure your ingredients our in your normal inventory especsially the creepy crawlies that you collect from the dungeon.