Someone using blizz pot

[Eco_Darwin]

Someone threw a blizz pot at me and I Cant join in oplifesteal, Every time I log in, It sents me back the the pika lobby. And say
Internal Exception: io.netty.handler.codec.EncoderException: java.lang.NullPointerException

 

[Kingxyz27]

Where this blizz pot is coming to players?
Is this legal ??

 

[UrfanTsk__28]

I also cant join for the same reason i dont know what to do.