Runtime in reader.dm, line 331: list index out of bounds

## Round ID:
N/A

## Testmerges:
N/A

## Reproduction:
Why do we not have an map issue template for the Snake?

ANYWAYS
On the snake

Start by reproducing the runtime on the Snake map and inspect reader.dm around line 331. Use the linked screenshot and the list index out of bounds error to identify the failing map data or lookup; done means the Snake no longer triggers this runtime under normal play.

Written by the indexing model from the issue text.