To start, my end goal is to modify the contents of a container the player has opened. From what I've seen (please correct me if I'm wrong), the easiest way to do that is to make a perk with a script that runs immediately on activating a container. To that end, I've made a new perk that triggers when the player opens a container. I have successfully added the perk to the player, but I'm having trouble getting the perk's script to trigger without crashing. I've included as much information as I can from the GECK -- if there's anything else I can add, please let me know.

Perk entry information:

Level: 0
Num Ranks: 1
Conditions: (blank)

I don't have the Trait, Playable, or Hidden checkboxes checked.

There's a single perk entry, as follows:
Rank: 1
Priority: 0
Entry Point: Activate
Function: Add Activate Choice
Button Label: (blank)
Run Immediately is checked.
Start Script body: ShowMessage TestMessage

Perk entry conditions:
Perk Owner: (none)
Target: S GetIsObjectType Container == 1.00

TestMessage is a message that should display "This is a test message." I've tried it with and without MessageBox checked, and I've tried it with and without Auto-display checked.

When I open a container, New Vegas crashes. Can anyone help me with my perk?