I found some minor issues in your model:
- The queue is not referenced correctly in 'Source: Item to Transport'. This is the cause of most of the error message you are getting. (The text should be purple if you are directly referencing an object)

- The 'ListProcessor' group used for the third instance doesn't exist in your model yet. There are also two small typos in the quantity field of the source ('LIst...', instead of 'List...' and 'Length' instead of 'length')

- The 'Create Task Sequence' activity after pulling the item from the list should reference Dispatcher3, so it can pass the task on to the operators.

- In the 'Pull from List' activity, you are ordering the items by the 'RushItem' label in descending order, meaning items with a label value of 0 are prioritized. The tutorial assumes that this should be the other way around.

I'll attach the fixed model as reference, but I would suggest you first try get your own model to run based on this post. Finding and fixing mistakes is quite an important skill to have in my opinion. 😉
13-lists-model_fm.fsm