Please HELP ME FOR THE LOVE OF GOD

Please HELP ME FOR THE LOVE OF GOD
i get this error please help me i have a gun and a knife for meh head and wrist

03:59:06 [SEVERE] java.io.IOException: Received string length longer than maximum allowed (34 > 32)
03:59:06 [SEVERE] at net.minecraft.server.Packet.a(Packet.java:120)
03:59:06 [SEVERE] at net.minecraft.server.Packet2Handshake.a(SourceFile:17)
03:59:06 [SEVERE] at net.minecraft.server.Packet.a(Packet.java:79)
03:59:06 [SEVERE] at net.minecraft.server.NetworkManager.h(NetworkManager.java:149)
03:59:06 [SEVERE] at net.minecraft.server.NetworkManager.c(NetworkManager.java:265)
03:59:06 [SEVERE] at net.minecraft.server.NetworkReaderThread.run(SourceFile:76)
please help meh for the children

[EDIT] this happens ONLY when some on join they get end of stream