Multiplayer crash when chucking items

crash error java.lang.NullPointerException: Ticking screen java.lang.NullPointerException: Ticking screenjava.lang.NullPointerException: Ticking screen at drm.d(SourceFile:184) at drm.j(SourceFile:251) at drm.g(SourceFile:241) at dqi.d(SourceFile:46) at djw.aR(SourceFile:1501) at djw$$Lambda$2749/627810315.run(Unknown Source) at doq.a(SourceFile:435) at djw.q(SourceFile:1501) at djw.e(SourceFile:996) at djw.e(SourceFile:656) at net.minecraft.client.main.Main.main(SourceFile:215) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at net.minecraft.launchwrapper.Launch.launch(Launch.java:159) at net.minecraft.launchwrapper.Launch.main(Launch.java:30)

When i was chucking items out my inventory my game froze and crashed.

This is the third time it has happened.