Crash immediately when opening Realms. probably something about snapshots though...

The crash info:

{{---- Minecraft Crash Report ----
// Oh - I know what I did wrong!

Time: 10/31/18 1:18 PM
Description: Rendering screen

java.lang.NoClassDefFoundError: net/minecraft/client/renderer/system/GlStateManager
at com.mojang.realmsclient.RealmsMainScreen.drawRealmsLogo(RealmsMainScreen.java:880)
at com.mojang.realmsclient.RealmsMainScreen.render(RealmsMainScreen.java:816)
at cop.a(SourceFile:102)
at czs.a(SourceFile:793)
at clp.d(SourceFile:850)
at clp.b(SourceFile:389)
at net.minecraft.client.main.Main.main(SourceFile:145)
Caused by: java.lang.ClassNotFoundException: net.minecraft.client.renderer.system.GlStateManager
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 7 more

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

– Head –
Thread: Client thread
Stacktrace:
at com.mojang.realmsclient.RealmsMainScreen.drawRealmsLogo(RealmsMainScreen.java:880)
at com.mojang.realmsclient.RealmsMainScreen.render(RealmsMainScreen.java:816)
at cop.a(SourceFile:102)

– Screen render details –
Details:
Screen name: cop
Mouse location: Scaled: (213, 165). Absolute: (426.000000, 331.000000)
Screen size: Scaled: (427, 240). Absolute: (854, 480). Scale factor of 2.000000
Stacktrace:
at czs.a(SourceFile:793)
at clp.d(SourceFile:850)
at clp.b(SourceFile:389)
at net.minecraft.client.main.Main.main(SourceFile:145)

– System Details –
Details:
Minecraft Version: 18w44a
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 1121762232 bytes (1069 MB) / 2113929216 bytes (2016 MB) up to 2147483648 bytes (2048 MB)
JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
Launched Version: 18w44a
LWJGL: 3.1.6 build 14
OpenGL: Intel(R) HD Graphics 520 GL version 4.5.0 - Build 23.20.16.4973, Intel
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)
CPU: 4x Intel(R) Core(TM) i5-6200U CPU @ 2.30GHz}}