How do you lock provinces?

[Knight Templar]

You know the thing where you click a province to highlight it, then hover the cursor over neighbour provinces to see the terrain type for battling across the border?

Will this data have to be amended too?

Will it trigger a crash if the user attempts this but the borders have been closed off in this way, or is it totally okay?

I'm not sure, but I think there should be no problems.

[Kekvit Irae]

If you follow my instructions above, there is no possible way to highlight the province, therefor there is no need to worry about hovering your mouse over for invasion info, because it's not there.