我的第一篇文章
运行游戏时FML导致崩溃
于ForgeGradle 3.+版本（Forge 1.12.2-14.23.5.2854及以上版本）运行游戏时崩溃，日志提示：Caught exception from Forge Mod Loader (FML)。
::: details 详细崩溃报告
1net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from Forge Mod Loader (FML)
2Caused by: java.lang.NullPointerException
3 at net.minecraftforge.fml.common.network.NetworkRegistry.newChannel(NetworkRegistry.java:207)
4 at net.minecraftforge.fml.common.network.internal.FMLNetworkHandler.registerChannel(FMLNetworkHandler.java:185)
5 at net.minecraftforge.fml.common.FMLContainer.modConstruction(FMLContainer.java:92)
6 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
7 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
8 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
9 at java.lang.reflect.Method.invoke(Method.java:498)
10 at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
11 at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
12 at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
13 at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
14 at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
15 at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
16 at com.google.common.eventbus.EventBus.post(EventBus.java:217)
17 at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:219)
18 at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:197)
19 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
20 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
21 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
22 at java.lang.reflect.Method.invoke(Method.java:498)
23 at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
24 at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
25 at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
26 at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
27 at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
28 at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
29 at com.google.common.eventbus.EventBus.post(EventBus.java:217)
30 at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:136)
31 at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:595)
32 at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:232)
33 at net.minecraft.client.Minecraft.init(Minecraft.java:467)
34 at net.minecraft.client.Minecraft.run(Minecraft.java:378)
35 at net.minecraft.client.main.Main.main(SourceFile:123)
36 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
37 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
38 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
39 at java.lang.reflect.Method.invoke(Method.java:498)
40 at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
41 at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
42 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
43 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
44 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
45 at java.lang.reflect.Method.invoke(Method.java:498)
46 at net.minecraftforge.legacydev.Main.start(Main.java:86)
47 at net.minecraftforge.legacydev.MainClient.main(MainClient.java:29)
:::
解决方案
在build.gradle文件的dependencies块中添加以下代码：
1dependencies {
2 // 添加以下代码强制使用旧版本mergetool
3 implementation ("net.minecraftforge:mergetool:0.2.3.3") { force = true }
4
5 // 其它依赖...
6}
随后删除C:\Users\<当前用户>\.gradle\caches\forge_gradle\minecraft_user_repo\net\minecraftforge\forge\1.12.2-14.23.5.xxxx_mapped_snapshot_xxxxxxxx-1.12或正在使用的Forge版本的文件夹，重新同步Gradle后修复。
如果上述方法无法修复，则可能是类路径中包的加载顺序问题，尝试使用fg.deobf提前mergetool的加载顺序：
1dependencies {
2 // 添加以下代码强制使用旧版本mergetool
3 implementation fg.deobf("net.minecraftforge:mergetool:0.2.3.3:forge") { force = true }
4
5 // 其它依赖...
6}