[21:20:32] [Server thread/INFO]: [TerrainControl] Enabling TerrainControl v2.6.0
[21:20:32] [Server thread/INFO]: [TerrainControl] [INFO] 0 Global custom objects loaded
[21:20:32] [Server thread/ERROR]: Error occurred while enabling TerrainControl v2.6.0 (Is it up to date?)
java.lang.NoClassDefFoundError: net/minecraft/server/v1_7_R3/WorldGenFactory
at com.khorn.terraincontrol.bukkit.TCPlugin.onEnable(TCPlugin.java:92) ~[?:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:316) ~[spigot.jar:git-Spigot-1548]
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:329) [spigot.jar:git-Spigot-1548]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [spigot.jar:git-Spigot-1548]
at org.bukkit.craftbukkit.v1_7_R4.CraftServer.loadPlugin(CraftServer.java:476) [spigot.jar:git-Spigot-1548]
at org.bukkit.craftbukkit.v1_7_R4.CraftServer.enablePlugins(CraftServer.java:394) [spigot.jar:git-Spigot-1548]
at net.minecraft.server.v1_7_R4.DedicatedServer.init(DedicatedServer.java:153) [spigot.jar:git-Spigot-1548]
at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:458) [spigot.jar:git-Spigot-1548]
at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [spigot.jar:git-Spigot-1548]
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.v1_7_R3.WorldGenFactory
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:67) ~[spigot.jar:git-Spigot-1548]
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:62) ~[spigot.jar:git-Spigot-1548]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_05]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_05]
... 9 more

For some reason it thinks it's still 2.6.0, because I am definitely running the dev build...

Specifically, I downloaded the top .jar on this page:
http://mctcp.com:8900/job/TerrainControl%20-%20Master%20-%20Gradle/default/26/

Build 26 failed due to an error in ForgeGradle (not my fault this time 😜, see here), the build server was probably serving up an old file.

Build 27 should be fine, except that the version number is still wrong. The file will still work.