Update v1.6.7.219072:
Performance and Stability Changes
To improve performance on Dedicated Servers we increased worker CPU threads from 1 to 4 by default. This should decrease loading times, to about 75% of time before, and in a smaller way speed up other tasks that game can do in parallel like pathfinding. 
If you are running DS locally, you will likely want to use the full 4 worker threads when needed. You can adjust this number by providing a command line argument to MoriaServer.exe, "-NumServerWorkerThreads=4". Range is from 1 to 4, although actual number could be lower than 4 if your CPU has less threads available. 
Note: Third party hosting services will provide their own value, or leave default, so please contact your provider to learn more about their solution.
Fixed a bug that was spawning multiples of the placeholder “citizen Dwarf” and reducing performance throughout the game
Improved an issue with the voxel engine that led to low framerate, lag spikes and high loading times for clients joining old or “mined-out” world areas. 
Fixed an issue that caused a lag spike when equipping an item
Fixed a bug where loading into a new area could have resulted in very long waiting times. This was most commonly seen when playing on Dedicated Server and teleporting into a distant new location with a mapstone.
Firing arrows no longer triggers the navmesh to rebuild, improving lag spikes and FPS.
Several improvements that should reduce the instances of long loading walls and long loading times
A package of improvements to performance for very large “megabases”
Removed several log spams that could happen due to data corruption or in special cases, which could decrease performance.
Fixed various crashes
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User Experience and Tuning Changes
Fixed an issue that was erroneously showing the “Buy Durin’s Folk” message every time the player launched the game or visited the main menu. It should now only appear a few times then never again.
The notification that an Earthquake occurred no longer appears after returning from every expedition.
Fixed several scenarios where players could get stuck in story Expeditions.
Fixed instances where Vror would not appear in story Expeditions.
Fixed several scenarios where players would fall through the world after returning from an expedition
Fixed an issue where some clients would see the names of all locations repeatedly, when entering a new area.
Package of tuning updates to the cost and payoff for traders has been delivered, to reduce the overall grind of trade goods and the trading economy
Trade Order recipes now stay unlocked once discovered
The new tribe of Orc that appears during the expansion will no longer appear during sieges and hordes after the completion of the story. They are still available in the highest difficulty of Expeditions.
Fixed a rare issue where getting knocked back in the base game’s final boss fight would deactivate some controls.
Fixed remaining issues where the Expansion’s boss would appear untextured.
Lord of Moria Banner and Moria Company Shield are now available in Sandbox
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NPC-related Changes
Work to improve several instances where NPCs were getting stuck
Fixed an issue that was limiting what Salvager would collect to an extremely limited set of items. Salvagers should now collect most things on the ground.
Fixed several instances of NPCs disappearing from a delving
Improved cases of enemies being able to walk through walls and closed doors
Fixed several issues that left the Cook and Brewmaster NPCs idle when they should be working
Decreased the amount of materials needed for crafting NPC hats and outfits
Improved the radius that Miners use to find ore
Fixed an issue where NPCs will craft using materials from pallets and other locations they should not have access to
Fixed an issue where Salvagers would duplicate materials they collected