10:59:01.332
net.minecraft.class_3503
main
Couldn't load fluid tag minecraft:water as it is missing following references: indrev:coolant_still (from Industrial Revolution),indrev:coolant_flowing (from Industrial Revolution),indrev:sulfuric_acid_still (from Industrial Revolution),indrev:sulfuric_acid_flowing (from Industrial Revolution),indrev:toxic_mud_still (from Industrial Revolution),indrev:toxic_mud_flowing (from Industrial Revolution)
10:59:01.333
net.minecraft.class_310
main
Failed to load datapacks, can't proceed with server load
java.util.concurrent.ExecutionException: java.lang.IllegalStateException: Missing required tags: minecraft:block:minecraft:buttons,minecraft:block:minecraft:doors,minecraft:block:minecraft:fences,minecraft:block:minecraft:leaves,minecraft:block:minecraft:logs,minecraft:block:minecraft:logs_that_burn,minecraft:block:minecraft:mushroom_grow_block,minecraft:block:minecraft:planks,minecraft:block:minecraft:pressure_plates,minecraft:block:minecraft:saplings,minecraft:block:minecraft:slabs,minecraft:block:minecraft:stairs,minecraft:block:minecraft:trapdoors,minecraft:block:minecraft:wall_post_override,minecraft:block:minecraft:walls,minecraft:block:minecraft:wooden_buttons,minecraft:block:minecraft:wooden_doors,minecraft:block:minecraft:wooden_fences,minecraft:block:minecraft:wooden_pressure_plates,minecraft:block:minecraft:wooden_slabs,minecraft:block:minecraft:wooden_stairs,minecraft:block:minecraft:wooden_trapdoors,minecraft:fluid:minecraft:lava,minecraft:fluid:minecraft:water,minecraft:item:minecraft:buttons,minecraft:item:minecraft:doors,minecraft:item:minecraft:fences,minecraft:item:minecraft:leaves,minecraft:item:minecraft:logs,minecraft:item:minecraft:logs_that_burn,minecraft:item:minecraft:planks,minecraft:item:minecraft:saplings,minecraft:item:minecraft:slabs,minecraft:item:minecraft:stairs,minecraft:item:minecraft:trapdoors,minecraft:item:minecraft:wooden_buttons,minecraft:item:minecraft:wooden_doors,minecraft:item:minecraft:wooden_fences,minecraft:item:minecraft:wooden_pressure_plates,minecraft:item:minecraft:wooden_slabs,minecraft:item:minecraft:wooden_stairs,minecraft:item:minecraft:wooden_trapdoors
at Not Enough Crashes deobfuscated stack trace.(1.16.4+build.9)
at java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357)
at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1908)
at net.minecraft.client.MinecraftClient.method_29604(MinecraftClient:1959)
at net.minecraft.client.MinecraftClient.startIntegratedServer(MinecraftClient:1808)
at net.minecraft.client.MinecraftClient.method_29608(MinecraftClient:1811)
at net.minecraft.client.gui.screen.DatapackFailureScreen.method_29346(DatapackFailureScreen:23)
at net.minecraft.client.gui.widget.ButtonWidget.onPress(ButtonWidget:33)
at net.minecraft.client.gui.widget.AbstractPressableButtonWidget.onClick(AbstractPressableButtonWidget:16)
at net.minecraft.client.gui.widget.AbstractButtonWidget.mouseClicked(AbstractButtonWidget:149)
at net.minecraft.client.gui.ParentElement.mouseClicked(ParentElement:27)
at net.minecraft.client.Mouse.method_1611(Mouse:92)
at net.minecraft.client.gui.screen.Screen.wrapScreenError(Screen:435)
at net.minecraft.client.Mouse.onMouseButton(Mouse:92)
at net.minecraft.client.Mouse.method_22686(Mouse:162)
at net.minecraft.util.thread.ThreadExecutor.execute(ThreadExecutor:94)
at net.minecraft.client.Mouse.method_22684(Mouse:162)
at org.lwjgl.glfw.GLFWMouseButtonCallbackI.callback(GLFWMouseButtonCallbackI.java:36)
at org.lwjgl.system.JNI.invokeV(Native Method)
at org.lwjgl.glfw.GLFW.glfwWaitEventsTimeout(GLFW.java:3174)
at com.mojang.blaze3d.systems.RenderSystem.limitDisplayFPS(RenderSystem:127)
at net.minecraft.client.MinecraftClient.render(MinecraftClient:1071)
at net.minecraft.client.MinecraftClient.run(MinecraftClient:681)
at net.minecraft.client.main.Main.main(Main:215)
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:498)
at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:226)
at net.fabricmc.loader.launch.knot.Knot.init(Knot.java:139)
at net.fabricmc.loader.launch.knot.KnotClient.main(KnotClient.java:27)
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:498)
at link.infra.jumploader.Jumploader.onLoad(Jumploader.java:171)
at cpw.mods.modlauncher.TransformationServiceDecorator.onLoad(TransformationServiceDecorator.java:53)
at cpw.mods.modlauncher.TransformationServicesHandler.lambda$loadTransformationServices$11(TransformationServicesHandler.java:131)
at java.util.HashMap$Values.forEach(HashMap.java:981)
at cpw.mods.modlauncher.TransformationServicesHandler.loadTransformationServices(TransformationServicesHandler.java:131)
at cpw.mods.modlauncher.TransformationServicesHandler.initializeTransformationServices(TransformationServicesHandler.java:56)
at cpw.mods.modlauncher.Launcher.run(Launcher.java:76)
at cpw.mods.modlauncher.Launcher.main(Launcher.java:66)
Caused by: java.lang.IllegalStateException: Missing required tags: minecraft:block:minecraft:buttons,minecraft:block:minecraft:doors,minecraft:block:minecraft:fences,minecraft:block:minecraft:leaves,minecraft:block:minecraft:logs,minecraft:block:minecraft:logs_that_burn,minecraft:block:minecraft:mushroom_grow_block,minecraft:block:minecraft:planks,minecraft:block:minecraft:pressure_plates,minecraft:block:minecraft:saplings,minecraft:block:minecraft:slabs,minecraft:block:minecraft:stairs,minecraft:block:minecraft:trapdoors,minecraft:block:minecraft:wall_post_override,minecraft:block:minecraft:walls,minecraft:block:minecraft:wooden_buttons,minecraft:block:minecraft:wooden_doors,minecraft:block:minecraft:wooden_fences,minecraft:block:minecraft:wooden_pressure_plates,minecraft:block:minecraft:wooden_slabs,minecraft:block:minecraft:wooden_stairs,minecraft:block:minecraft:wooden_trapdoors,minecraft:fluid:minecraft:lava,minecraft:fluid:minecraft:water,minecraft:item:minecraft:buttons,minecraft:item:minecraft:doors,minecraft:item:minecraft:fences,minecraft:item:minecraft:leaves,minecraft:item:minecraft:logs,minecraft:item:minecraft:logs_that_burn,minecraft:item:minecraft:planks,minecraft:item:minecraft:saplings,minecraft:item:minecraft:slabs,minecraft:item:minecraft:stairs,minecraft:item:minecraft:trapdoors,minecraft:item:minecraft:wooden_buttons,minecraft:item:minecraft:wooden_doors,minecraft:item:minecraft:wooden_fences,minecraft:item:minecraft:wooden_pressure_plates,minecraft:item:minecraft:wooden_slabs,minecraft:item:minecraft:wooden_stairs,minecraft:item:minecraft:wooden_trapdoors
at net.minecraft.tag.TagManagerLoader.method_30224(TagManagerLoader:49)
at java.util.concurrent.CompletableFuture.uniAccept(CompletableFuture.java:670)
at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:646)
at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:456)
at net.minecraft.resource.ResourceReloader.method_18365(ResourceReloader:71)
at net.minecraft.util.thread.ThreadExecutor.executeTask(ThreadExecutor:144)
at net.minecraft.util.thread.ReentrantThreadExecutor.executeTask(ReentrantThreadExecutor:23)
at net.minecraft.util.thread.ThreadExecutor.runTask(ThreadExecutor:118)
at net.minecraft.util.thread.ThreadExecutor.runTasks(ThreadExecutor:127)
at net.minecraft.client.MinecraftClient.method_29604(MinecraftClient:1958)
... 39 more
The version of prefab: Latest
Minecraft version- 1.16.4

I was able to load the game and generate a structure properly.

Game Version: 1.16.4
Mod Versions:

1. Prefab: 1.0.2
2. Industrial Revolution: 1.8.10-BETA
3. Fabric-API: 0.31.0
4. Fabric Loader: 0.11.2

I noticed mentions of "cpw.mods.modlauncher". Did you launch this from a Overwolf/Twitch installation? That app doesn't work well with Fabric installations as it's made for Forge installations.

My examples were with the standard Minecraft Launcher and mod folders.

Screen Shots:

This is a Overwolf install

With jumploader

Was able to start the game.

Also loaded a world

Here's my modlist

there are other mods

Please provide the full mod list so I can troubleshoot this further.

Thank you.

Closing as there has been no communication in 13 days.