Game crashes when I make a mod that adds new countries

[Zook03]

I'm trying to make a mod that creates a few new countries in North America and gives them states that would normally be owned by the USA at game start. The mod loads up fine but as soon as I press play the game crashes with the following error:

Application: Victoria 3
Version: 1.7.5
Date/Time: 2024-08-10 02:52:22

Unhandled Exception C0000005 (EXCEPTION_ACCESS_VIOLATION) at address 0x00007FF6CE5E3CF8

I'll attach the mod files and the error dump so that someone can figure out what the problem is - I have a suspicion it's something to do with pops or buildings but I'm not sure.