<https://forums.minecraftforge.net/topic/102611-when-i-enter-the-game-with-forge-the-error-appears-without-forge-the-game-works-normally-my-game-version-is-117/#comment-460871>
<http://schema.org/text>
"20:38:52.071\n \n\n\n\tgame\n \n\n\n\tat MC-BOOTSTRAP/fmlloader@1.17.1-37.0.5/net.minecraftforge.fml.loading.targets.CommonClientLaunchHandler.lambda$launchService$0(CommonClientLaunchHandler.java:45)\n \n\n\n\t20:38:52.071\n \n\n\n\tgame\n \n\n\n\tat MC-BOOTSTRAP/cpw.mods.modlauncher@9.0.7/cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37)\n \n\n\n\t20:38:52.071\n \n\n\n\tgame\n \n\n\n\t... 7 more\n \n\n\n\t20:38:52.071\n \n\n\n\tgame\n \n\n\n\tCaused by: java.lang.RuntimeException: java.lang.IllegalAccessError: class net.minecraftforge.registries.GameData$ClearableObjectIntIdentityMap tried to access private field net.minecraft.core.IdMapper.f_122654_ (net.minecraftforge.registries.GameData$ClearableObjectIntIdentityMap is in module forge@37.0.5 of loader 'TRANSFORMER' @6bfdb014; net.minecraft.core.IdMapper is in module minecraft@1.17.1 of loader 'TRANSFORMER' @6bfdb014)\n \n\n\n\t20:38:52.071\n \n\n\n\tgame\n \n\n\n\tat MC-BOOTSTRAP/fmlloader@1.17.1-37.0.5/net.minecraftforge.fml.loading.BackgroundWaiter.runAndTick(BackgroundWaiter.java:43)\n \n\n\n\t20:38:52.071\n \n\n\n\tgame\n \n\n\n\tat TRANSFORMER/minecraft@1.17.1/net.minecraft.client.main.Main.main(Main.java:125)\n \n\n\n\t20:38:52.071\n \n\n\n\tgame\n \n\n\n\t... 13 more\n \n\n\n\t20:38:52.078\n \n\n\n\tgame\n \n\n\n\tCaused by: java.lang.IllegalAccessError: class net.minecraftforge.registries.GameData$ClearableObjectIntIdentityMap tried to access private field net.minecraft.core.IdMapper.f_122654_ (net.minecraftforge.registries.GameData$ClearableObjectIntIdentityMap is in module forge@37.0.5 of loader 'TRANSFORMER' @6bfdb014; net.minecraft.core.IdMapper is in module minecraft@1.17.1 of loader 'TRANSFORMER' @6bfdb014)\n \n\n\n\t20:38:52.116\n \n\n\n\tgame\n \n\n\n\tat TRANSFORMER/forge@37.0.5/net.minecraftforge.registries.GameData$ClearableObjectIntIdentityMap.clear(GameData.java:418)\n \n\n\n\t20:38:52.116\n \n\n\n\tgame\n \n\n\n\tat TRANSFORMER/forge@37.0.5/net.minecraftforge.registries.GameData$BlockCallbacks.onClear(GameData.java:471)\n \n\n\n\t20:38:52.116\n \n\n\n\tgame\n \n\n\n\tat TRANSFORMER/forge@37.0.5/net.minecraftforge.registries.ForgeRegistry.sync(ForgeRegistry.java:539)\n \n\n\n\t20:38:52.116\n \n\n\n\tgame\n \n\n\n\tat TRANSFORMER/forge@37.0.5/net.minecraftforge.registries.GameData.loadRegistry(GameData.java:695)\n \n\n\n\t20:38:52.116\n \n\n\n\tgame\n \n\n\n\tat TRANSFORMER/forge@37.0.5/net.minecraftforge.registries.GameData.vanillaSnapshot(GameData.java:269)\n \n\n\n\t20:38:52.117\n \n\n\n\tgame\n \n\n\n\tat TRANSFORMER/minecraft@1.17.1/net.minecraft.server.Bootstrap.m_135870_(Bootstrap.java:53)\n \n\n\n\t20:38:52.117\n \n\n\n\tgame\n \n\n\n\tat TRANSFORMER/minecraft@1.17.1/net.minecraft.client.main.Main.lambda$main$0(Main.java:125)\n \n\n\n\t20:38:52.117\n \n\n\n\tgame\n \n\n\n\tat java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)\n \n\n\n\t20:38:52.117\n \n\n\n\tgame\n \n\n\n\tat java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)\n \n\n\n\t20:38:52.117\n \n\n\n\tgame\n \n\n\n\tat java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)\n \n\n\n\t20:38:52.117\n \n\n\n\tgame\n \n\n\n\tat java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)\n \n\n\n\t20:38:52.117\n \n\n\n\tgame\n \n\n\n\tat java.base/java.lang.Thread.run(Thread.java:831)\n \n\n\n\t20:38:54.572\n \n\n\n\tmonitor\n \n\n\n\tProcess Monitor\n \n\n\n\tProcess crashed with exit code 1\n \n"
<https://forums.minecraftforge.net/topic/102611-when-i-enter-the-game-with-forge-the-error-appears-without-forge-the-game-works-normally-my-game-version-is-117/?tab=comments#comment-460832>