From my experience with roads, you can't use the editor to place them. You must use the Road tool. Since you mentioned DayZEditor I personally suggest going to their discord for that help, they are quiet quick at helping if you need, but will tell you the same thing regarding roads.

In T165965#2328158, @Geez wrote:

Hello System32.
You need to launch the game with -nonavmesh if it is intentional that there is no navmesh.
Regards,
Geez

Thanks @Geez - I would assume this has only been since 1.18? As before that update, I have been able to run without a navmesh since I started. The navmesh & ce are both not valid because I dont feel the need for them right now due to creating the map first.

So i've reinstalled windows, and the error still persist after re-installing everything required for a terrain.