Hey so some friends and I set up a custom Minecraft 1.16.3 modpack on Forge 34.1.42 and created a server to run it. The server is up and running and we have connected once last night to test it. However when I first connected java would freeze up on me due to endless NullPointerException fatal errors in the game output log. Looking into the errors around those fatals I found that I am getting an Error while loading contents for several of the books.

Below is just 2 of them.

10:23:44.783
Error while loading contents for book ars_nouveau:worn_notebook
java.lang.RuntimeException: Error building entry ars_nouveau:machines/volcanic_accumulator
at vazkii.patchouli.client.book.BookContents.lambda$reload$5(BookContents.java:141)
at vazkii.patchouli.client.book.BookContents$$Lambda$22517/740352882.accept(Unknown Source)
at java.util.HashMap$Values.forEach(HashMap.java:972)
at vazkii.patchouli.client.book.BookContents.reload(BookContents.java:137)
at vazkii.patchouli.common.book.Book.reloadContents(Book.java:186)
at vazkii.patchouli.common.book.BookRegistry$$Lambda$22507/1714319649.accept(Unknown Source)
at java.util.HashMap$Values.forEach(HashMap.java:972)
at vazkii.patchouli.common.book.BookRegistry.reloadContents(BookRegistry.java:104)
at vazkii.patchouli.client.book.ClientBookRegistry.reload(ClientBookRegistry.java:63)
at vazkii.patchouli.client.base.ClientAdvancements.onClientPacket(ClientAdvancements.java:40)
at net.minecraft.client.multiplayer.ClientAdvancementManager.handler$zfa000$patchouli_onSync(SourceFile:518)
at net.minecraft.client.multiplayer.ClientAdvancementManager.func_192799_a(SourceFile:57)
at net.minecraft.client.network.play.ClientPlayNetHandler.func_191981_a(ClientPlayNetHandler.java:1275)
at net.minecraft.network.play.server.SAdvancementInfoPacket.func_148833_a(SourceFile:37)
at net.minecraft.network.play.server.SAdvancementInfoPacket.func_148833_a(SourceFile:16)
at net.minecraft.network.PacketThreadUtil.func_225383_a(SourceFile:21)
at net.minecraft.network.PacketThreadUtil$$Lambda$22047/666681959.run(Unknown Source)
at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213166_h(SourceFile:144)
at net.minecraft.util.concurrent.RecursiveEventLoop.func_213166_h(SourceFile:23)
at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213168_p(SourceFile:118)
at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213160_bf(SourceFile:103)
at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:924)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:584)
at net.minecraft.client.main.Main.main(Main.java:184)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:51)
at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$473/1380137286.call(Unknown Source)
at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37)
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54)
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72)
at cpw.mods.modlauncher.Launcher.run(Launcher.java:82)
at cpw.mods.modlauncher.Launcher.main(Launcher.java:66)
Caused by: java.lang.RuntimeException: Error while loading entry ars_nouveau:machines/volcanic_accumulator page 2
at vazkii.patchouli.client.book.BookEntry.build(BookEntry.java:224)
at vazkii.patchouli.client.book.BookContents.lambda$reload$5(BookContents.java:139)
... 34 more
Caused by: java.lang.NullPointerException
at vazkii.patchouli.client.book.page.abstr.PageDoubleRecipeRegistry.getRecipe(PageDoubleRecipeRegistry.java:29)
at vazkii.patchouli.client.book.page.abstr.PageDoubleRecipeRegistry.loadRecipe(PageDoubleRecipeRegistry.java:46)
at vazkii.patchouli.client.book.page.abstr.PageDoubleRecipeRegistry.loadRecipe(PageDoubleRecipeRegistry.java:19)
at vazkii.patchouli.client.book.page.abstr.PageDoubleRecipe.build(PageDoubleRecipe.java:27)
at vazkii.patchouli.client.book.BookEntry.build(BookEntry.java:221)
... 35 more
10:23:44.981
Error while loading contents for book mythicbotany:lexicon
java.lang.RuntimeException: Error building entry botania:baubles/ice_pendant
at vazkii.patchouli.client.book.BookContents.lambda$reload$5(BookContents.java:141)
at vazkii.patchouli.client.book.BookContents$$Lambda$22517/740352882.accept(Unknown Source)
at java.util.HashMap$Values.forEach(HashMap.java:972)
at vazkii.patchouli.client.book.BookContents.reload(BookContents.java:137)
at vazkii.patchouli.common.book.Book.reloadExtensionContents(Book.java:211)
at vazkii.patchouli.common.book.BookRegistry$$Lambda$22536/160187977.accept(Unknown Source)
at java.util.HashMap$Values.forEach(HashMap.java:972)
at vazkii.patchouli.common.book.BookRegistry.reloadContents(BookRegistry.java:105)
at vazkii.patchouli.client.book.ClientBookRegistry.reload(ClientBookRegistry.java:63)
at vazkii.patchouli.client.base.ClientAdvancements.onClientPacket(ClientAdvancements.java:40)
at net.minecraft.client.multiplayer.ClientAdvancementManager.handler$zfa000$patchouli_onSync(SourceFile:518)
at net.minecraft.client.multiplayer.ClientAdvancementManager.func_192799_a(SourceFile:57)
at net.minecraft.client.network.play.ClientPlayNetHandler.func_191981_a(ClientPlayNetHandler.java:1275)
at net.minecraft.network.play.server.SAdvancementInfoPacket.func_148833_a(SourceFile:37)
at net.minecraft.network.play.server.SAdvancementInfoPacket.func_148833_a(SourceFile:16)
at net.minecraft.network.PacketThreadUtil.func_225383_a(SourceFile:21)
at net.minecraft.network.PacketThreadUtil$$Lambda$22047/666681959.run(Unknown Source)
at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213166_h(SourceFile:144)
at net.minecraft.util.concurrent.RecursiveEventLoop.func_213166_h(SourceFile:23)
at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213168_p(SourceFile:118)
at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213160_bf(SourceFile:103)
at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:924)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:584)
at net.minecraft.client.main.Main.main(Main.java:184)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:51)
at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$473/1380137286.call(Unknown Source)
at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37)
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54)
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72)
at cpw.mods.modlauncher.Launcher.run(Launcher.java:82)
at cpw.mods.modlauncher.Launcher.main(Launcher.java:66)
Caused by: java.lang.RuntimeException: Error while loading entry botania:baubles/ice_pendant page 1
at vazkii.patchouli.client.book.BookEntry.build(BookEntry.java:224)
at vazkii.patchouli.client.book.BookContents.lambda$reload$5(BookContents.java:139)
... 34 more
Caused by: java.lang.NullPointerException
at vazkii.patchouli.client.book.page.abstr.PageDoubleRecipeRegistry.getRecipe(PageDoubleRecipeRegistry.java:29)
at vazkii.patchouli.client.book.page.abstr.PageDoubleRecipeRegistry.loadRecipe(PageDoubleRecipeRegistry.java:46)
at vazkii.patchouli.client.book.page.abstr.PageDoubleRecipeRegistry.loadRecipe(PageDoubleRecipeRegistry.java:19)
at vazkii.patchouli.client.book.page.abstr.PageDoubleRecipe.build(PageDoubleRecipe.java:27)
at vazkii.patchouli.client.book.BookEntry.build(BookEntry.java:221)
... 35 more

This issue is stale because it has been open for a while with no activity. Please bump if this is still an issue, or this ticket will be closed soon.