List indices must be numeric

I’m having problems identifying the problem I have with the Codeblock. This only happens when im using this, seems like it has something to do with the empty Original Category list, but cant seem to figure out why i comes out empty.

I have been following a guide by Autodesk University for the Script, where i get no problem using it for their test model, but when i use it on my own model, i seem to run in to these problems.

What does the error says?

It says “List indices must be numeric”

Is there is a single null in the data set causing an issue?

No. There isn’t any nulls in the data set.