ART Pattern Usage Error

[Gabogg07]

Hello! I am trying to insert a pattern inside a bargraph and i get this shadow node error. I already tried other parts of the code and this seems to be the problem (if i change "pattern" for a hex color value it works just fine). I really need to fill the bars with different patterns because I'm trying to simulate stratographic columns (Geology).

Thanks in advance for you help.

Error :

Error Place:

Pattern Usage: