this is the error log:
[10:12:29] [Server thread/ERROR] [FML]: A fatal exception occurred during the server starting event
net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from Open Terrain Generator (openterraingenerator)
Caused by: java.lang.RuntimeException: OTG has detected that you are loading an OTG world that has been used without OTG installed. OTG has fixed and saved the world data, you can now restart the game and enter the world.
at com.pg85.otg.forge.OTGPlugin.serverLoad(OTGPlugin.java:212) ~[OTGPlugin.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_144]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_144]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_144]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_144]
at net.minecraftforge.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:624) ~[server.jar:?]
at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source) ~[?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_144]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_144]
at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:217) ~[minecraft_server.1.12.2.jar:?]
at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:218) ~[server.jar:?]
at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:196) ~[server.jar:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_144]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_144]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_144]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_144]
at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116) ~[minecraft_server.1.12.2.jar:?]
at com.google.common.eventbus.EventBus.post(EventBus.java:217) ~[minecraft_server.1.12.2.jar:?]
at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:135) ~[LoadController.class:?]
at net.minecraftforge.fml.common.Loader.serverStarting(Loader.java:794) [Loader.class:?]
at net.minecraftforge.fml.common.FMLCommonHandler.handleServerStarting(FMLCommonHandler.java:297) [FMLCommonHandler.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:307) [nz.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:486) [MinecraftServer.class:?]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_144]
[10:12:29] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Stopping server
[10:12:29] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Saving players
[10:12:29] [Server thread/INFO] [net.minecraft.server.MinecraftServer]: Saving worlds
[
[10:12:30] [Server thread/TRACE] [FML]: Sending event FMLServerStoppedEvent to mod minecraft
[10:12:30] [Server thread/TRACE] [FML]: Sent event FMLServerStoppedEvent to mod minecraft
[10:12:30] [Server thread/DEBUG] [FML]: Bar Step: ServerStopped - Minecraft took 0.000s
[10:12:30] [Server thread/INFO] [FML]: The state engine was in incorrect state SERVER_STARTING and forced into state SERVER_STOPPED. Errors may have been discarded.
[10:12:30] [Server Shutdown Thread/INFO] [net.minecraft.server.MinecraftServer]: Stopping server