Something changed in patchouli and was never fixed in rebornstorage.
[09:49:10] [Worker-ResourceReload-9/ERROR]:Failed to load book rebornstorage:rs_book defined by mod rebornstorage, skipping
java.lang.IllegalArgumentException: Book rebornstorage:rs_book has use_resource_pack set to false. This behaviour was removed in 1.20. The book author should enable this flag and move all book contents clientside to /assets/, leaving the book.json in /data/. See https://vazkiimods.github.io/Patchouli/docs/upgrading/upgrade-guide-120 for details.
at vazkii.patchouli.common.book.Book.(Book.java:145) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at vazkii.patchouli.common.book.BookRegistry.loadBook(BookRegistry.java:90) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at vazkii.patchouli.common.book.BookRegistry.lambda$init$3(BookRegistry.java:75) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at java.util.HashMap.forEach(Unknown Source) ~[?:?]
at vazkii.patchouli.common.book.BookRegistry.init(BookRegistry.java:70) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at vazkii.patchouli.forge.common.ForgeModInitializer.onInitialize(ForgeModInitializer.java:76) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at vazkii.patchouli.forge.common.__ForgeModInitializer_onInitialize_FMLCommonSetupEvent.invoke(.dynamic) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:55) ~[eventbus-6.2.33.jar%2387!/:?]
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:312) ~[eventbus-6.2.33.jar%2387!/:?]
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:298) ~[eventbus-6.2.33.jar%2387!/:?]
at net.minecraftforge.fml.javafmlmod.FMLModContainer.acceptEvent(FMLModContainer.java:121) ~[javafmllanguage-1.20.1-47.4.20.jar%23854!/:?]
at net.minecraftforge.fml.ModContainer.lambda$buildTransitionHandler$5(ModContainer.java:127) ~[fmlcore-1.20.1-47.4.20.jar%23853!/:?]
at java.util.concurrent.CompletableFuture$AsyncRun.run(Unknown Source) ~[?:?]
at java.util.concurrent.CompletableFuture$AsyncRun.exec(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinTask.doExec(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinPool.scan(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinPool.runWorker(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source) ~[?:?]
Something changed in patchouli and was never fixed in rebornstorage.
[09:49:10] [Worker-ResourceReload-9/ERROR]:Failed to load book rebornstorage:rs_book defined by mod rebornstorage, skipping
java.lang.IllegalArgumentException: Book rebornstorage:rs_book has use_resource_pack set to false. This behaviour was removed in 1.20. The book author should enable this flag and move all book contents clientside to /assets/, leaving the book.json in /data/. See https://vazkiimods.github.io/Patchouli/docs/upgrading/upgrade-guide-120 for details.
at vazkii.patchouli.common.book.Book.(Book.java:145) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at vazkii.patchouli.common.book.BookRegistry.loadBook(BookRegistry.java:90) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at vazkii.patchouli.common.book.BookRegistry.lambda$init$3(BookRegistry.java:75) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at java.util.HashMap.forEach(Unknown Source) ~[?:?]
at vazkii.patchouli.common.book.BookRegistry.init(BookRegistry.java:70) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at vazkii.patchouli.forge.common.ForgeModInitializer.onInitialize(ForgeModInitializer.java:76) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at vazkii.patchouli.forge.common.__ForgeModInitializer_onInitialize_FMLCommonSetupEvent.invoke(.dynamic) ~[Patchouli-1.20.1-85-FORGE.jar%23756!/:1.20.1-85-FORGE]
at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:55) ~[eventbus-6.2.33.jar%2387!/:?]
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:312) ~[eventbus-6.2.33.jar%2387!/:?]
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:298) ~[eventbus-6.2.33.jar%2387!/:?]
at net.minecraftforge.fml.javafmlmod.FMLModContainer.acceptEvent(FMLModContainer.java:121) ~[javafmllanguage-1.20.1-47.4.20.jar%23854!/:?]
at net.minecraftforge.fml.ModContainer.lambda$buildTransitionHandler$5(ModContainer.java:127) ~[fmlcore-1.20.1-47.4.20.jar%23853!/:?]
at java.util.concurrent.CompletableFuture$AsyncRun.run(Unknown Source) ~[?:?]
at java.util.concurrent.CompletableFuture$AsyncRun.exec(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinTask.doExec(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinPool.scan(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinPool.runWorker(Unknown Source) ~[?:?]
at java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source) ~[?:?]