Crash when clicking on 'Minecraft Realms' button

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(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	... 7 more