My game doesn't start but I don't know what's wrong.

What should I do?

The contents of the error file:

---- Minecraft Crash Report -------- Minecraft Crash Report ----// Surprise! Haha. Well, this is awkward.
Time: 2019.05.01. 0:16Description: Initializing game
java.lang.NullPointerException: Initializing game at cty.<init>(SourceFile:21) at dkx.<init>(SourceFile:16) at cvi.av(SourceFile:464) at cvi.b(SourceFile:395) at net.minecraft.client.main.Main.main(SourceFile:154)

A detailed walkthrough of the error, its code path and all known details is as follows:---------------------------------------------------------------------------------------
– Head --Thread: Client threadStacktrace: at cty.<init>(SourceFile:21) at dkx.<init>(SourceFile:16) at cvi.av(SourceFile:464)
– Initialization --Details:Stacktrace: at cvi.b(SourceFile:395) at net.minecraft.client.main.Main.main(SourceFile:154)
– System Details --Details: Minecraft Version: 1.14 Operating System: Windows 8 (amd64) version 6.2 Java Version: 1.8.0_51, Oracle Corporation Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation Memory: 1062066296 bytes (1012 MB) / 1509949440 bytes (1440 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: 1.14 LWJGL: 3.2.1 build 12 OpenGL: NO CONTEXT GL Caps:  Using VBOs: Yes Is Modded: Probably not. Jar signature remains and client brand is untouched. Type: Client (map_client.txt) Resource Packs:  Current Language: ~_ERROR~ NullPointerException: null CPU: <unknown>