Ah, that is what happened. When you create a Variable, it is usually to put some information that comes from the user, so you just use the GetMaterial dictionary (if you don’t mind whether it is a color, a gradient or a pattern) OR you extract the [‘Color’] key value if you need only a color. So, it looks like the pattern name you put might have a different spelling than the actual pattern, which means that PSP could not recognize it.
You were trying to put the whole recipe instead of the name of the Tupperware container! 😉