Analyze: This phase does not handle this header 4 (0x4)(phase: AUTH)

I got this error after I compiled the client binary.
Now I can't login to my game server.

Error:
Analyze: This phase does not handle this header 4 (0x4)(phase: AUTH)

Does somebody know what this mean?

It means exactly what it says.
Your auth phase packet handler doesn't recognize the packet id 4.
Either your packet id's on server or client side don't match, the packet structure of the previous packet doesn't match with the servers packet structure or you're sending a sequence byte even though the server requires you not to do so.

Hast du die Packet improved kacke ausgemacht im Serversource, aber nicht im Clienten?
Hatte den Fehler vor 5 Tagen mal, ist schnell behoben.