Server crash when launching fireworks

No problems in single player..
In multiplayer, when launching fireworks by hand, from launcher, the server terminates layer connection reporting end of stream. Server does not crash, but reports the following for each attempt to launch fireworks.

java.lang.NullPointerException
at ef.a(SourceFile:310)
at mj.a(SourceFile:237)
at mj.a(SourceFile:157)
at et.a(SourceFile:36)
at ef.a(SourceFile:214)
at cg.h(SourceFile:178)
at cg.d(SourceFile:15)
at ci.run(SourceFile:114)