This is a weird issue/bug that I just came across:
prefix does not seem to be a viable name for a variable. It returns an EOF error.
So far I’ve noticed the issue in 2.17, 2.18, and 2.19. Is there some hidden property or class that uses this name that I’m unaware of?
It is not in the known list of keywords:
Weird 
Looks to be a Parser error, but nothing obvious at first glance. We’ll file a task to look at it 
CC @Michael_Kirschner2
prefix is a reserved keyword from the old DesignScript language syntax. We will clean this up. Thanks for pointing this out @Nick_Boyts!
