does not let me to a server or a player to enter a server I designed this java.lang.PullPointerException : Group please help me

will not let me enter server or player aparese me this when entering a server java.lang.NullPointerException : group
help

• He told me the error when entering a server this: java.lang.NullPointerException : group ... *

Entering a server and play com my partner

• let go java.lang.NullPointerException error : Group *
  empese to find solution but found no one and not juge : c

Steps to Reproduce:
1- not seeeeee !!!!!!!!!!!!!!!!!!!!!!!!!!
2. ...
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