I would like to bring what i believe is a bug on forge side to your attention, tested and verified to be happening both in 1.16.3 and 1.16.4. When using the bee spawn egg to change the entity inside a spawner the console keeps spamming this error (though the game does not actually crash):

 

[14nov2020 02:01:50.879] [Render thread/FATAL] [net.minecraftforge.common.ForgeMod/]: Preparing crash report with UUID ff74860d-b4ef-4698-b95c-17dae8737e90
[14nov2020 02:01:50.879] [Render thread/WARN] [net.minecraft.entity.EntityType/]: Exception loading entity: 
net.minecraft.crash.ReportedException: Loading entity NBT
	at net.minecraft.entity.Entity.read(Entity.java:1672) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.entity.EntityType.lambda$loadEntityUnchecked$2(EntityType.java:461) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.util.Util.acceptOrElse(Util.java:321) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.entity.EntityType.loadEntityUnchecked(EntityType.java:458) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.entity.EntityType.loadEntity(EntityType.java:516) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.entity.EntityType.loadEntityAndExecute(EntityType.java:498) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.world.spawner.AbstractSpawner.getCachedEntity(AbstractSpawner.java:255) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.renderer.tileentity.MobSpawnerTileEntityRenderer.render(MobSpawnerTileEntityRenderer.java:24) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.renderer.tileentity.MobSpawnerTileEntityRenderer.render(MobSpawnerTileEntityRenderer.java:14) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.renderer.tileentity.TileEntityRendererDispatcher.render(TileEntityRendererDispatcher.java:101) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.renderer.tileentity.TileEntityRendererDispatcher.lambda$renderTileEntity$0(TileEntityRendererDispatcher.java:85) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.renderer.tileentity.TileEntityRendererDispatcher.runCrashReportable(TileEntityRendererDispatcher.java:121) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.renderer.tileentity.TileEntityRendererDispatcher.renderTileEntity(TileEntityRendererDispatcher.java:84) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.renderer.WorldRenderer.updateCameraAndRender(WorldRenderer.java:1060) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.renderer.GameRenderer.renderWorld(GameRenderer.java:619) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.renderer.GameRenderer.updateCameraAndRender(GameRenderer.java:437) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1002) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.Minecraft.run(Minecraft.java:612) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.client.main.Main.main(Main.java:184) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_192]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_192]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_192]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_192]
	at net.minecraftforge.userdev.FMLUserdevClientLaunchProvider.lambda$launchService$0(FMLUserdevClientLaunchProvider.java:52) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-8.0.6.jar:?]
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-8.0.6.jar:?]
	at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-8.0.6.jar:?]
	at cpw.mods.modlauncher.Launcher.run(Launcher.java:82) [modlauncher-8.0.6.jar:?]
	at cpw.mods.modlauncher.Launcher.main(Launcher.java:66) [modlauncher-8.0.6.jar:?]
	at net.minecraftforge.userdev.LaunchTesting.main(LaunchTesting.java:105) [forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
Caused by: java.lang.ClassCastException: net.minecraft.client.world.ClientWorld cannot be cast to net.minecraft.world.server.ServerWorld
	at net.minecraft.entity.passive.BeeEntity.readAdditional(BeeEntity.java:190) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	at net.minecraft.entity.Entity.read(Entity.java:1657) ~[forge-1.16.4-35.0.2_mapped_snapshot_20201028-1.16.3-recomp.jar:?]
	... 29 more

 

I should note this happens in a fresh new environment, when there is nohing but the basic mod setup code. Also it seems to happen only with the bee spawn egg..i discovered this because i was implementing an entity that can get the form (visually) of any EntityType, using code inspired by the spawner tile entity, and when i got to test it with the bee entity it actually crashed the game (probably due to poor code on my side)..so i tested what happened if i tried to change the spawner entity to a Bee and the above error was thrown

 

Edit: this error seems to happen also with the following entities: zombified piglin, wolf, polar bear and enderman

Edited November 14, 20204 yr by Beethoven92

So, this seems to be a vanilla thing.

Namely they don't seem to ever give you a spawner with entities in it so the client trying to render it never tries to render bees or wolves or whatever.

If you can find a way to give yourself these items in vanilla, then it should probably be reported to Mojang.

57 minutes ago, diesieben07 said:

The same is true for endermen.

Definitely a vanilla bug: https://bugs.mojang.com/browse/MC-189565

Aha good find! Of course i did some research for any matching vanilla bug before reporting an issue here, but for whatever reason i did non manage to find this..unfortunately the bug seems to have been fixed only in the first 1.17 snapshot