Hello.
Thanks for your immediate update!
I tried new beta file but it crashed.
Log message is below.

[23:10:23]
[Server thread/ERROR]: Encountered an unexpected exception
ava.lang.NoClassDefFoundError: net/minecraft/client/renderer/texture/ITextureObject
at net.shadowmage.ancientwarfare.structure.block.BlockStructureBuilder.func_149666_a(BlockStructureBuilder.java:40) ~[BlockStructureBuilder.class:?]
at net.minecraft.item.ItemBlock.func_150895_a(ItemBlock.java:149) ~[ahb.class:?]
at crafttweaker.mc1120.item.MCItemUtils.createItemList(MCItemUtils.java:38) ~[MCItemUtils.class:?]
at crafttweaker.mc1120.brackets.BracketHandlerItem.rebuildItemRegistry(BracketHandlerItem.java:63) ~[BracketHandlerItem.class:?]
at crafttweaker.mc1120.events.CommonEventHandler.registerRecipes(CommonEventHandler.java:39) ~[CommonEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_54_CommonEventHandler_registerRecipes_Register.invoke(.dynamic) ~[?:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90) ~[ASMEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.EventBus$1.invoke(EventBus.java:143) ~[EventBus$1.class:?]
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:179) ~[EventBus.class:?]
at net.minecraftforge.registries.GameData.fireRegistryEvents(GameData.java:746) ~[GameData.class:?]
at net.minecraftforge.common.crafting.CraftingHelper.loadRecipes(CraftingHelper.java:622) ~[CraftingHelper.class:?]
at net.minecraftforge.fml.common.Loader.initializeMods(Loader.java:717) ~[Loader.class:?]
at net.minecraftforge.fml.server.FMLServerHandler.finishServerLoading(FMLServerHandler.java:107) ~[FMLServerHandler.class:?]
at net.minecraftforge.fml.common.FMLCommonHandler.onServerStarted(FMLCommonHandler.java:336) ~[FMLCommonHandler.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:219) ~[nz.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484) [MinecraftServer.class:?]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_151]
Caused by: java.lang.ClassNotFoundException: net.minecraft.client.renderer.texture.ITextureObject
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191) ~[launchwrapper-1.12.jar:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_151]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_151]
... 17 more
Caused by: java.lang.NullPointerException
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182) ~[launchwrapper-1.12.jar:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_151]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_151]
... 17 more
[23:10:23] [Server thread/ERROR]: This crash report has been saved to: /home/hirota/Forge1.12.2/./crash-reports/crash-2017-12-05_23.10.23-server.txt
[23:10:23] [Server thread/INFO]: Stopping server
[23:10:23] [Server thread/INFO]: Saving worlds
[23:10:23] [Server Shutdown Thread/INFO]: Stopping server
[23:10:23] [Server Shutdown Thread/INFO]: Saving worlds

Looks like you will only get this crash with craft tweaker, but that part of the code could potentially be accessed by some other mod that tries to load sub blocks on dedicated server as well. So I have added a bit of code so that this works with those.

Could you test this build and see if that works for you? https://bintray.com/p3pp3rf1y/maven/download_file?file_path=ancientwarfare-1.12.2-2.4.26unstable.jar

It seems ok, and scanning structures is working fine!
Thank you :-)

crash report

--- Minecraft Crash Report ----
WARNING: coremods are present:
Contact their authors BEFORE contacting forge
// Why did you do that?
Time: 17/12/05 23:13
Description: Exception in server tick loop
java.lang.NoClassDefFoundError: net/minecraft/client/renderer/texture/ITextureObject
at net.shadowmage.ancientwarfare.structure.block.BlockStructureBuilder.func_149666_a(BlockStructureBuilder.java:40)
at net.minecraft.item.ItemBlock.func_150895_a(ItemBlock.java:149)
at crafttweaker.mc1120.item.MCItemUtils.createItemList(MCItemUtils.java:38)
at crafttweaker.mc1120.brackets.BracketHandlerItem.rebuildItemRegistry(BracketHandlerItem.java:63)
at crafttweaker.mc1120.events.CommonEventHandler.registerRecipes(CommonEventHandler.java:39)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_54_CommonEventHandler_registerRecipes_Register.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus$1.invoke(EventBus.java:143)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:179)
at net.minecraftforge.registries.GameData.fireRegistryEvents(GameData.java:746)
at net.minecraftforge.common.crafting.CraftingHelper.loadRecipes(CraftingHelper.java:622)
at net.minecraftforge.fml.common.Loader.initializeMods(Loader.java:717)
at net.minecraftforge.fml.server.FMLServerHandler.finishServerLoading(FMLServerHandler.java:107)
at net.minecraftforge.fml.common.FMLCommonHandler.onServerStarted(FMLCommonHandler.java:336)
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:219)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: net.minecraft.client.renderer.texture.ITextureObject
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 17 more
Caused by: java.lang.NullPointerException
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182)
... 19 more
A detailed walkthrough of the error, its code path and all known details is as follows:
-- System Details --
Details:
Minecraft Version: 1.12.2
Operating System: Linux (amd64) version 2.6.32-696.13.2.el6.x86_64
Java Version: 1.8.0_151, Oracle Corporation
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 1539927000 bytes (1468 MB) / 2058354688 bytes (1963 MB) up to 2058354688 bytes (1963 MB)
JVM Flags: 2 total; -Xmx2048M -Xms2048M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP 9.42 Powered by Forge 14.23.1.2555 15 mods loaded, 15 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
| State | ID | Version | Source | Signature
|
|:----- |:----------------------------------------- |:------------ |:------------------------------------------- |:--------------------------------
-------- |
| UCH | minecraft | 1.12.2 | minecraft.jar | None
|
| UCH | mcp | 9.42 | minecraft.jar | None
|
| UCH | FML | 8.0.99.99 | minecraftforge.jar | e3c3d50c7c986df74c645c0ac5463974
1c90a557 |
| UCH | forge | 14.23.1.2555 | minecraftforge.jar | e3c3d50c7c986df74c645c0ac5463974
1c90a557 |
| UCH | codechickenlib | 3.1.3.313 | CodeChickenLib-1.12-3.1.3.313-universal.jar | f1850c39b2516232a2108a7bd84d1cb5
df93b261 |
| UCH | ancientwarfare | @Version@ | ancientwarfare-1.12.2-2.4.24.jar | None
|
| UCH | ancientwarfareautomation | @Version@ | ancientwarfare-1.12.2-2.4.24.jar | None
|
| UCH | ancientwarfarenpc | @Version@ | ancientwarfare-1.12.2-2.4.24.jar | None
|
| UCH | ancientwarfarestructure | @Version@ | ancientwarfare-1.12.2-2.4.24.jar | None
|
| UCH | bibliocraft | 2.4.3 | BiblioCraft-Mod-1.12.jar | None
|
| UCH | crafttweaker | 4.0.10 | CraftTweaker2-1.12-4.0.10.jar | None
|
| UCH | crafttweakerjei | 2.0.0 | CraftTweaker2-1.12-4.0.10.jar | None
|
| UCH | net.minecraft.scalar.cutall.mod_cutallsmp | 2.5.2 | CutAllSMP_v2.5.2.zip | None
|
| UCH | spawnchecker | 2.7.7.137 | SpawnChecker-2.7.7.137.jar | 26e70d58815b73cd7c6c865fe091672f
79070a35 |
| UCH | spawnchecker.presetmode | 2.7.7.137 | SpawnChecker-2.7.7.137.jar | 26e70d58815b73cd7c6c865fe091672f
79070a35 |
Loaded coremods (and transformers):
Profiler Position: N/A (disabled)
Is Modded: Definitely; Server brand changed to 'fml,forge'
Type: Dedicated Server (map_server.txt)

This is resolved in the latest release