NPC waypoint issues

I am aware of a few NPCS that are walking threw walls and actual land mases. I am currently working on this issue. If you have already dealt with this issue feel free to comment and explain.

ALL NPCs are currently doing this. Even when "running away in fear" or chasing me outdoors on flat surfaces I have had them clip through the ground as well as run straight up into the air. I believe it to be a case of either corrupted, missing or disabled mmaps file for the server.