Client v176 - MWLR_Login

hi i am trying to create a client for swordie version 176 when i launch the server and then the clienton the server it throws the following error

[DEBUG] [PacketEncoder] | Plain sending CHECK_PASSWORD_RESULT, 0/0x0 | B0 00 01 00 31 52 30 19 73 46 72 1E 52 08 00 java.lang.IndexOutOfBoundsException: readerIndex(6) + length(2) exceeds writerIndex(7): UnpooledHeapByteBuf(ridx: 6, widx: 7, cap: 7/7)