why

---- Minecraft Crash Report ----
// Don't do that.

Time: 2/16/20 2:14 PM
Description: Initializing game

java.lang.NullPointerException: Initializing game
	at net.minecraftforge.fml.loading.progress.EarlyProgressVisualization.join(EarlyProgressVisualization.java:40) ~[forge-1.15.2-31.1.0_mapped_snapshot_20190719-1.14.3-launcher.jar:?] {}
	at net.minecraft.client.Minecraft.<init>(Minecraft.java:371) [forge-1.15.2-31.1.0_mapped_snapshot_20190719-1.14.3-recomp.jar:?] {}
	at net.minecraft.client.main.Main.main(Main.java:141) [forge-1.15.2-31.1.0_mapped_snapshot_20190719-1.14.3-recomp.jar:?] {}
	at mcp.client.Start.main(Start.java:17) [forge-1.15.2-31.1.0_mapped_snapshot_20190719-1.14.3-recomp.jar:?] {}


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

-- Head --
Thread: Render thread
Stacktrace:
	at net.minecraftforge.fml.loading.progress.EarlyProgressVisualization.join(EarlyProgressVisualization.java:40)
	at net.minecraft.client.Minecraft.<init>(Minecraft.java:371)

-- Initialization --
Details:
Stacktrace:
	at net.minecraft.client.main.Main.main(Main.java:141)
	at mcp.client.Start.main(Start.java:17)

-- System Details --
Details:
	Minecraft Version: 1.15.2
	Minecraft Version ID: 1.15.2
	Operating System: Windows 10 (amd64) version 10.0
	Java Version: 1.8.0_222, AdoptOpenJDK
	Java VM Version: OpenJDK 64-Bit Server VM (mixed mode),
	Memory: 751758512 bytes (716 MB) / 922222592 bytes (879 MB) up to 2852126720 bytes (2720 MB)
	CPUs: 8
	JVM Flags: 0 total;
	Launched Version: mcp
	Backend library: LWJGL version 3.2.2 build 10
	Backend API: NO CONTEXT
	GL Caps:
	Using VBOs: Yes
	Is Modded: Definitely; Client brand changed to 'forge'
	Type: Client (map_client.txt)
	CPU: <unknown>