Crash my server

Hi, how are you? I'm bad:(: because I not find a solution for my problem details:
Players(Hacker, Lammer, as your preference) crash my Gs, this error is new because my server was online for more of 4 months and today crash.
Wpe, crash for guild not found also I tried disabling the guilds.
Ddos is blocked from hardware.
Udp flood blocked.
I don't have more idea, sorry for my bad english.