I got a random crash I don't know what crash it is, but this is what the crash report said
"---- Minecraft Crash Report ----
// Ooh. Shiny.

Time: 2/15/18 8:23 PM
Description: Unexpected error

java.lang.ClassCastException: cby$b cannot be cast to amn
at cda.a(SourceFile:39)
at ccy.f(SourceFile:84)
at ccy.a(SourceFile:73)
at ccx.c(SourceFile:186)
at ccx.a(SourceFile:114)
at ccx.a(SourceFile:78)
at ccg.c(SourceFile:56)
at cau.a(SourceFile:310)
at bxe.a(SourceFile:728)
at bxe.av(SourceFile:1335)
at bxe.m(SourceFile:1220)
at bxe.b(SourceFile:791)
at bxe.a(SourceFile:381)
at net.minecraft.client.main.Main.main(SourceFile:141)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Thread: Client thread
Stacktrace:
at cda.a(SourceFile:39)
at ccy.f(SourceFile:84)
at ccy.a(SourceFile:73)
at ccx.c(SourceFile:186)
at ccx.a(SourceFile:114)
at ccx.a(SourceFile:78)
at ccg.c(SourceFile:56)
at cau.a(SourceFile:310)
at bxe.a(SourceFile:728)
at bxe.av(SourceFile:1335)

– Affected level –
Details:
Level name: MpServer
All players: 1 total; [cjq['Drinarii'/460, l='MpServer', x=156.72, y=64.26, z=-11.75]]
Chunk stats: MultiplayerChunkCache: 49, 49
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (95,64,27), Chunk: (at 15,4,11 in 5,1; contains blocks 80,0,16 to 95,255,31), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 76113 game time, 36702 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
Forced entities: 2 total; [aij['Trident'/193, l='MpServer', x=150.78, y=62.58, z=-22.63], cjq['Drinarii'/460, l='MpServer', x=156.72, y=64.26, z=-11.75]]
Retry entities: 0 total; []
Server brand: vanilla
Server type: Integrated singleplayer server
Stacktrace:
at chn.a(SourceFile:368)
at bxe.b(SourceFile:1827)
at bxe.a(SourceFile:394)
at net.minecraft.client.main.Main.main(SourceFile:141)

– System Details –
Details:
Minecraft Version: 18w07b
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 184351928 bytes (175 MB) / 553648128 bytes (528 MB) up to 1073741824 bytes (1024 MB)
JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=16M
Launched Version: 18w07b
LWJGL: 3.1.2 build 29
OpenGL: GeForce 9800 GT/PCIe/SSE2 GL version 3.3.0, NVIDIA Corporation
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

Using VBOs: Yes
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs:
Current Language: English (US)
Profiler Position: N/A (disabled)
CPU: 4x Intel(R) Core(TM)2 Quad CPU Q8400 @ 2.66GHz"