Server crashes when receiving chat messages

[quantumproducer]

And the front end continuously asks me for a username when I try to send a message.

=ERROR REPORT==== 11-Mar-2017::12:55:03 ===
Ranch listener http had connection process started with cowboy_protocol:start_link/4 at <0.327.0> exit with reason: {[{reason,undef},{mfa,{ws_handler,init,2}},{stacktrace,[{ebus_handler,new,[bus_listener,<0.327.0>],[]},{ws_handler,init,2,[{file,"/Users/quantum/code/chatBus/_build/default/lib/chatbus/src/ws_handler.erl"},{line,16}]},{cowboy_handler,execute,2,[{file,"/Users/quantum/code/chatBus/_build/default/lib/cowboy/src/cowboy_handler.erl"},{line,39}]},{cowboy_protocol,execute,4,[{file,"/Users/quantum/code/chatBus/_build/default/lib/cowboy/src/cowboy_protocol.erl"},{line,428}]}]},{req,[{socket,#Port<0.1563>},{transport,ranch_tcp},{connection,keepalive},{pid,<0.327.0>},{method,<<"GET">>},{version,'HTTP/1.1'},{peer,{{127,0,0,1},51041}},{host,<<"localhost">>},{host_info,undefined},{port,9090},{path,<<"/ws">>},{path_info,undefined},{qs,<<>>},{bindings,[]},{headers,[{<<"host">>,<<"localhost:9090">>},{<<"user-agent">>,<<"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Firefox/52.0">>},{<<"accept">>,<<"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8">>},{<<"accept-language">>,<<"en-US,en;q=0.5">>},{<<"accept-encoding">>,<<"gzip, deflate">>},{<<"sec-websocket-version">>,<<"13">>},{<<"origin">>,<<"http://localhost:9090">>},{<<"sec-websocket-extensions">>,<<"permessage-deflate">>},{<<"sec-websocket-key">>,<<"aIUM0+n1KSLgfh4oS/rTyw==">>},{<<"dnt">>,<<"1">>},{<<"connection">>,<<"keep-alive, Upgrade">>},{<<"pragma">>,<<"no-cache">>},{<<"cache-control">>,<<"no-cache">>},{<<"upgrade">>,<<"websocket">>}]},{meta,[]},{body_state,waiting},{buffer,<<>>},{multipart,undefined},{resp_compress,false},{resp_state,waiting},{resp_headers,[]},{resp_body,<<>>},{onresponse,undefined}]},{opts,[]}],[{cowboy_protocol,execute,4,[{file,"/Users/quantum/code/chatBus/_build/default/lib/cowboy/src/cowboy_protocol.erl"},{line,428}]}]}

[fishballian]

because ebus have removed ebus_handler module
#3