NEVERMIND! She reinstalled her java again( the same way I did). She surprisingly joined

We both play with cracked minecraft (Tlauncher), now she's making the server, but once her server is online, I'm the only one that can connect again, she's still having this issue. I'll tell her to update her java or something. Hopefully it would work? hehe

After how many hours of trying to start my server, I finally joined. But the issue is, my friend is having this issue while joining my server

"internal exception io.netty.handler.codec.decoderexception: Java.IOException: Bad packet id 26 ".

I don't know how to fix this issue. I already read the threads regarding this issue but I still don't understand how changing the username is going to fix this error. Please reply asap, I haven't done anything in the server yet since I'm trying to look for solutions. Thanks!