You will find the fix in the downloads section. The fix is a small file and is save-game compatible (it is the updated module.ini).
The reason I did not detect the terrain borders errors is because I had the op_terrain borders resources in my common resources folder and my module.ini referenced those brfs instead of the brfs in the module resources folder. Anyway, the terrain border resources (brfs) and textures are already in the mod so all you will need is the updated module.ini in this fix
Please please please fix the nords! They are too powerful in sieges they'll demolish your heavy troops in the first 30 seconds of the siege! Then the rest is even more slaughter.... Even in easiest modes they'll kill you in three hits... ( Iwas in plated armour too!)
Are you playing version 1.0 or version 1.1? Are you the castle defender or attacker?
In Native Warband, the main advantage of the Nords was their effectiveness in sieges.