I see a couple of issues with this mod.
It doesn't have any contingency plan for situations where there is no client planting the brick.
If there is no client, there is no SuperAdmin, even if the owner of that brickgroup is supposed to have Auto SuperAdmin when he joins.
Essentially when loading bricks, there might be no client, so it might fail certain permission checks where it should not.
I also see issues with the preferences not saving. It looks like some misspelled variable names will cause it to reset some preferences to default values every time the server restarts.
I've attached a version of the server.cs that might work with loading. Added like- 2 lines. Didn't test it cause it's like 5 AM and I can't be bothered.
I hope it works out for ya.