Spam of errors, while next to iron golem spawner

When I'm next to iron golem spawner on servers I get spammed by these errors and logs are getting houndreds of GB by that. In spawner there is no mob inside. I tried to reproduce problem on single player and iron golem spawner after a while turns into pig, but error still happens and after putting spawner on ground it has no mob inside.

[20:02:01] [main/INFO]: [STDOUT]: Negative index in crash report handler (0/25)
[20:02:01] [main/WARN]: Exception loading entity: 
u: Loading entity NBT
	at apx.f(SourceFile:1663) ~[apx.class:?]
	at aqb.a(SourceFile:473) ~[aqb.class:?]
	at x.a(Util.java:414) ~[x.class:?]
	at aqb.a(SourceFile:472) ~[aqb.class:?]
	at aqb.b(SourceFile:535) ~[aqb.class:?]
	at aqb.a(SourceFile:516) ~[aqb.class:?]
	at bqw.d(SourceFile:254) ~[bqw.class:?]
	at ech.a(SourceFile:22) ~[ech.class:?]
	at ech.a(SourceFile:12) ~[ech.class:?]
	at ebv.a(TileEntityRendererDispatcher.java:126) ~[ebv.class:?]
	at ebv.lambda$renderTileEntity$0(TileEntityRendererDispatcher.java:101) ~[ebv.class:?]
	at ebv.a(TileEntityRendererDispatcher.java:185) [ebv.class:?]
	at ebv.a(TileEntityRendererDispatcher.java:99) [ebv.class:?]
	at dzw.a(WorldRenderer.java:1801) [dzw.class:?]
	at dzr.a(GameRenderer.java:1022) [dzr.class:?]
	at dzr.a(GameRenderer.java:693) [dzr.class:?]
	at djw.e(SourceFile:1023) [djw.class:?]
	at djw.e(SourceFile:656) [djw.class:?]
	at net.minecraft.client.main.Main.main(SourceFile:215) [Main.class:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_251]
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_251]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_251]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_251]
	at net.minecraft.launchwrapper.Launch.launch(Launch.java:159) [launchwrapper-of-2.2.jar:2.2]
	at net.minecraft.launchwrapper.Launch.main(Launch.java:30) [launchwrapper-of-2.2.jar:2.2]
Caused by: java.lang.ClassCastException