Game crashes seemingly without reason

All I did was put an item back in my creative inventory to destroy it.
That second the game crashed.
The world is broken now.

Using the shift key worked.

java.lang.NullPointerException: Unexpected error
	at agv.a(SourceFile:1120)
	at bkt.h(SourceFile:1598)
	at bkt.a(SourceFile:1178)
	at bkt.b(SourceFile:1163)
	at bkt.a(SourceFile:1010)
	at bab.as(SourceFile:954)
	at bab.a(SourceFile:377)
	at net.minecraft.client.main.Main.main(SourceFile:125)