Looks like it erroneously replaces some icons.

Update: Yes, I get all kind of strange symbols instead of icons.

3.14159...

Nah, that's a Russian "L".

The problem has been solved, the mod was unable to find paths to the icons due to some folder names.

I wonder if the fact that I created the Australian civ is just a coincidence...

EDIT: Aww, so it was just a coincidence that it looked like Pi at all...