Here you have the crash report.

[05Nov2022 13:28:30.284] [modloading-worker-3/FATAL] [net.minecraftforge.fml.loading.RuntimeDistCleaner/DISTXFORM]: Attempted to load class net/minecraft/client/gui/screen/Screen for invalid dist DEDICATED_SERVER
242 | [05Nov2022 13:28:30.285] [modloading-worker-3/ERROR] [net.minecraftforge.fml.javafmlmod.FMLModContainer/]: Exception caught during firing event: Attempted to load class net/minecraft/client/gui/screen/Screen for invalid dist DEDICATED_SERVER
243 | Index: 1
244 | Listeners:
245 | 0: NORMAL
246 | 1: net.minecraftforge.eventbus.EventBus$Lambda$2672/1405521573@30b80813
247 | java.lang.RuntimeException: Attempted to load class net/minecraft/client/gui/screen/Screen for invalid dist DEDICATED_SERVER
248 | at net.minecraftforge.fml.loading.RuntimeDistCleaner.processClassWithFlags(RuntimeDistCleaner.java:71)
249 | at cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:85)
250 | at cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:120)
251 | at cpw.mods.modlauncher.TransformingClassLoader$DelegatedClassLoader.findClass(TransformingClassLoader.java:265)
252 | at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:136)
253 | at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:98)
254 | at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
255 | at java.lang.invoke.MethodHandleNatives.resolve(Native Method)
256 | at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:975)
257 | at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:1000)
258 | at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1394)
259 | at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1750)
260 | at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477)
261 | at com.skullmangames.darksouls.network.ModNetworkManager.registerPackets(ModNetworkManager.java:101)
262 | at com.skullmangames.darksouls.DarkSouls.doCommonStuff(DarkSouls.java:169)
263 | at net.minecraftforge.eventbus.EventBus.doCastFilter(EventBus.java:247)
264 | at net.minecraftforge.eventbus.EventBus.lambda$addListener$11(EventBus.java:239)
265 | at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302)
266 | at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283)
267 | at net.minecraftforge.fml.javafmlmod.FMLModContainer.acceptEvent(FMLModContainer.java:120)
268 | at net.minecraftforge.fml.ModContainer.lambda$buildTransitionHandler$4(ModContainer.java:121)
269 | at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1640)
270 | at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1632)
271 | at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
272 | at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
273 | at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
274 | at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:175)
275 |  
276 | [05Nov2022 13:28:30.289] [modloading-worker-3/ERROR] [net.minecraftforge.fml.javafmlmod.FMLModContainer/LOADING]: Caught exception during event FMLCommonSetupEvent dispatch for modid darksouls
277 | java.lang.RuntimeException: Attempted to load class net/minecraft/client/gui/screen/Screen for invalid dist DEDICATED_SERVER
278 | at net.minecraftforge.fml.loading.RuntimeDistCleaner.processClassWithFlags(RuntimeDistCleaner.java:71) ~[forge.jar:36.2]
279 | at cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:85) ~[modlauncher-8.1.3.jar:?]
280 | at cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:120) ~[modlauncher-8.1.3.jar:?]
281 | at cpw.mods.modlauncher.TransformingClassLoader$DelegatedClassLoader.findClass(TransformingClassLoader.java:265) ~[modlauncher-8.1.3.jar:?]
282 | at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:136) ~[modlauncher-8.1.3.jar:?]
283 | at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:98) ~[modlauncher-8.1.3.jar:?]
284 | at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_352]
285 | at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[?:1.8.0_352]
286 | at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:975) ~[?:1.8.0_352]
287 | at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:1000) ~[?:1.8.0_352]
288 | at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1394) ~[?:1.8.0_352]
289 | at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1750) ~[?:1.8.0_352]
290 | at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477) ~[?:1.8.0_352]
291 | at com.skullmangames.darksouls.network.ModNetworkManager.registerPackets(ModNetworkManager.java:101) ~[darksouls:1.0]
292 | at com.skullmangames.darksouls.DarkSouls.doCommonStuff(DarkSouls.java:169) ~[darksouls:1.0]
293 | at net.minecraftforge.eventbus.EventBus.doCastFilter(EventBus.java:247) ~[eventbus-4.0.0.jar:?]
294 | at net.minecraftforge.eventbus.EventBus.lambda$addListener$11(EventBus.java:239) ~[eventbus-4.0.0.jar:?]
295 | at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) ~[eventbus-4.0.0.jar:?]
296 | at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) ~[eventbus-4.0.0.jar:?]
297 | at net.minecraftforge.fml.javafmlmod.FMLModContainer.acceptEvent(FMLModContainer.java:120) ~[forge:36.2]
298 | at net.minecraftforge.fml.ModContainer.lambda$buildTransitionHandler$4(ModContainer.java:121) ~[forge:?]
299 | at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1640) [?:1.8.0_352]
300 | at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1632) [?:1.8.0_352]
301 | at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289) [?:1.8.0_352]
302 | at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056) [?:1.8.0_352]
303 | at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692) [?:1.8.0_352]
304 | at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:175) [?:1.8.0_352]
305 | [05Nov2022 13:28:30.335] [main/FATAL] [net.minecraftforge.fml.ModLoader/LOADING]: Failed to complete lifecycle event COMMON_SETUP, 1 errors found
306 | [05Nov2022 13:28:30.367] [main/DEBUG] [net.minecraftforge.fml.ForgeI18n/CORE]: Loading I18N data entries: 4980
307 | [05Nov2022 13:28:30.371] [main/FATAL] [net.minecraftforge.common.ForgeMod/]: Preparing crash report with UUID 212cfcc6-9162-40c9-acbd-3548a7e8797e
308 | [05Nov2022 13:28:30.381] [main/INFO] [STDOUT/]: [net.minecraft.crash.CrashReport:func_85057_a:196]: Negative index in crash report handler (16/18)
309 | [05Nov2022 13:28:30.397] [main/FATAL] [net.minecraftforge.fml.server.ServerModLoader/]: Crash report saved to ./crash-reports/crash-2022-11-05_13.28.30-fml.txt
310 | [05Nov2022 13:28:30.406] [main/FATAL] [net.minecraft.server.Main/]: Failed to start the minecraft server
311 | net.minecraftforge.fml.LoadingFailedException: Loading errors encountered: [
312 | Minecraft: Dark Souls (darksouls) encountered an error during the common_setup event phase
313 | §7java.lang.RuntimeException: Attempted to load class net/minecraft/client/gui/screen/Screen for invalid dist DEDICATED_SERVER
314 | ]
315 | at net.minecraftforge.fml.ModLoader.waitForTransition(ModLoader.java:269) ~[forge:?]
316 | at net.minecraftforge.fml.ModLoader.dispatchAndHandleError(ModLoader.java:236) ~[forge:?]
317 | at net.minecraftforge.fml.ModLoader.loadMods(ModLoader.java:211) ~[forge:?]
318 | at net.minecraftforge.fml.server.ServerModLoader.load(ServerModLoader.java:45) ~[forge:?]
319 | at net.minecraft.server.Main.main(Main.java:95) ~[?:?]
320 | at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_352]
321 | at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_352]
322 | at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_352]
323 | at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_352]
324 | at net.minecraftforge.fml.loading.FMLServerLaunchProvider.lambda$launchService$0(FMLServerLaunchProvider.java:51) ~[forge.jar:36.2]
325 | at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-8.1.3.jar:?]
326 | at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-8.1.3.jar:?]
327 | at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-8.1.3.jar:?]
328 | at cpw.mods.modlauncher.Launcher.run(Launcher.java:82) [modlauncher-8.1.3.jar:?]
329 | at cpw.mods.modlauncher.Launcher.main(Launcher.java:66) [modlauncher-8.1.3.jar:?]
330 | at net.minecraftforge.server.ServerMain$Runner.runLauncher(ServerMain.java:63) [forge.jar:?]
331 | at net.minecraftforge.server.ServerMain$Runner.access$100(ServerMain.java:60) [forge.jar:?]
332 | at net.minecraftforge.server.ServerMain.main(ServerMain.java:57) [forge.jar:?]
333

[05Nov2022 13:28:30.289] [modloading-worker-3/ERROR] [net.minecraftforge.fml.javafmlmod.FMLModContainer/LOADING]: Caught exception during event FMLCommonSetupEvent dispatch for modid darksouls
java.lang.RuntimeException: Attempted to load class net/minecraft/client/gui/screen/Screen for invalid dist DEDICATED_SERVER
at net.minecraftforge.fml.loading.RuntimeDistCleaner.processClassWithFlags(RuntimeDistCleaner.java:71) ~[forge.jar:36.2]
at cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:85) ~[modlauncher-8.1.3.jar:?]
at cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:120) ~[modlauncher-8.1.3.jar:?]
at cpw.mods.modlauncher.TransformingClassLoader$DelegatedClassLoader.findClass(TransformingClassLoader.java:265) ~[modlauncher-8.1.3.jar:?]
at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:136) ~[modlauncher-8.1.3.jar:?]
at cpw.mods.modlauncher.TransformingClassLoader.loadClass(TransformingClassLoader.java:98) ~[modlauncher-8.1.3.jar:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_352]
at java.lang.invoke.MethodHandleNatives.resolve(Native Method) ~[?:1.8.0_352]
at java.lang.invoke.MemberName$Factory.resolve(MemberName.java:975) ~[?:1.8.0_352]
at java.lang.invoke.MemberName$Factory.resolveOrFail(MemberName.java:1000) ~[?:1.8.0_352]
at java.lang.invoke.MethodHandles$Lookup.resolveOrFail(MethodHandles.java:1394) ~[?:1.8.0_352]
at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1750) ~[?:1.8.0_352]
at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:477) ~[?:1.8.0_352]
at com.skullmangames.darksouls.network.ModNetworkManager.registerPackets(ModNetworkManager.java:101) ~[darksouls:1.0]
at com.skullmangames.darksouls.DarkSouls.doCommonStuff(DarkSouls.java:169) ~[darksouls:1.0]
at net.minecraftforge.eventbus.EventBus.doCastFilter(EventBus.java:247) ~[eventbus-4.0.0.jar:?]
at net.minecraftforge.eventbus.EventBus.lambda$addListener$11(EventBus.java:239) ~[eventbus-4.0.0.jar:?]
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) ~[eventbus-4.0.0.jar:?]
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) ~[eventbus-4.0.0.jar:?]
at net.minecraftforge.fml.javafmlmod.FMLModContainer.acceptEvent(FMLModContainer.java:120) ~[forge:36.2]
at net.minecraftforge.fml.ModContainer.lambda$buildTransitionHandler$4(ModContainer.java:121) ~[forge:?]
at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1640) [?:1.8.0_352]
at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1632) [?:1.8.0_352]
at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289) [?:1.8.0_352]
at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056) [?:1.8.0_352]
at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692) [?:1.8.0_352]
at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:175) [?:1.8.0_352]
[05Nov2022 13:28:30.335] [main/FATAL] [net.minecraftforge.fml.ModLoader/LOADING]: Failed to complete lifecycle event COMMON_SETUP, 1 errors found
[05Nov2022 13:28:30.367] [main/DEBUG] [net.minecraftforge.fml.ForgeI18n/CORE]: Loading I18N data entries: 4980
[05Nov2022 13:28:30.371] [main/FATAL] [net.minecraftforge.common.ForgeMod/]: Preparing crash report with UUID 212cfcc6-9162-40c9-acbd-3548a7e8797e
[05Nov2022 13:28:30.381] [main/INFO] [STDOUT/]: [net.minecraft.crash.CrashReport:func_85057_a:196]: Negative index in crash report handler (16/18)
[05Nov2022 13:28:30.397] [main/FATAL] [net.minecraftforge.fml.server.ServerModLoader/]: Crash report saved to ./crash-reports/crash-2022-11-05_13.28.30-fml.txt
[05Nov2022 13:28:30.406] [main/FATAL] [net.minecraft.server.Main/]: Failed to start the minecraft server
net.minecraftforge.fml.LoadingFailedException: Loading errors encountered: [
Minecraft: Dark Souls (darksouls) encountered an error during the common_setup event phase
§7java.lang.RuntimeException: Attempted to load class net/minecraft/client/gui/screen/Screen for invalid dist DEDICATED_SERVER
]
at net.minecraftforge.fml.ModLoader.waitForTransition(ModLoader.java:269) ~[forge:?]
at net.minecraftforge.fml.ModLoader.dispatchAndHandleError(ModLoader.java:236) ~[forge:?]
at net.minecraftforge.fml.ModLoader.loadMods(ModLoader.java:211) ~[forge:?]
at net.minecraftforge.fml.server.ServerModLoader.load(ServerModLoader.java:45) ~[forge:?]
at net.minecraft.server.Main.main(Main.java:95) ~[?:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_352]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_352]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_352]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_352]
at net.minecraftforge.fml.loading.FMLServerLaunchProvider.lambda$launchService$0(FMLServerLaunchProvider.java:51) ~[forge.jar:36.2]
at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-8.1.3.jar:?]
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-8.1.3.jar:?]
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-8.1.3.jar:?]
at cpw.mods.modlauncher.Launcher.run(Launcher.java:82) [modlauncher-8.1.3.jar:?]
at cpw.mods.modlauncher.Launcher.main(Launcher.java:66) [modlauncher-8.1.3.jar:?]
at net.minecraftforge.server.ServerMain$Runner.runLauncher(ServerMain.java:63) [forge.jar:?]
at net.minecraftforge.server.ServerMain$Runner.access$100(ServerMain.java:60) [forge.jar:?]
at net.minecraftforge.server.ServerMain.main(ServerMain.java:57) [forge.jar:?]

I just have the mod. No other mods included

Thank you. I see the problem. It is one of those where I the mod accidentally runs code on the server that should only be run on client. I don't know if I will fix this issue on the 0.3 version. You may have to wait for the big version 0.4.0 to come out.

Thx. I am very excited to play it.