One of my players is getting constanly kicked from my server. She says it doesn't happen on any other server. It also doesn't happen to any other of my players so i doubt that's server side error.

Kick messages that she got are:
Internal Exception io.netty.handler.codec.CorruptedFrameException: lenght wider than 21-bit

Internal Exception io.netty.handler.codec.DecoderException: java.lang.RuntimeException: VarInt too big

Internal Exception: io.netty.handler.codec.DecoderWxception: java.land.IndexOutOfBoundsException: readerIndex(914569) + lenght(1) exceeds writerIndex(14569): UnpooledHeapByteBuf(ridx: 14569, widx: 14569, cap: 14569/14569)

Internal Exception: io.netty.handler.codec.DecoderException: Badly compressed packet - sice of 24 is below server treshold of 256

Thing happens as with optifine, as without it.
Same goes for any resourcepacks installed.