diff --git a/src/common/mainloop.rs b/src/common/mainloop.rs
index 1e6448b..341a66f 100644
--- a/src/common/mainloop.rs
+++ b/src/common/mainloop.rs
@@ -36,8 +36,16 @@ fn recv_from_clientpool<STATE, S, R, E>(state: &mut STATE,
                     },
                     ClientPoolAction::Packet(client_id, pkt) => {
                         let to_send = state.handle(client_id, &pkt);
-                        for s in to_send {
-                            pool_send.send(ClientAction::Packet(s.0, s.1)).unwrap();
+                        match to_send {
+                            Ok(pkts) =>  {
+                                for p in pkts {
+                                    pool_send.send(ClientAction::Packet(p.0, p.1)).unwrap();
+                                }
+                            },
+                            Err(err) => {
+                                // TODO: break?
+                                println!("[handler error]: {:?} {:?}", client_id, err);
+                            }
                         }
                     }
                 }
diff --git a/src/common/serverstate.rs b/src/common/serverstate.rs
index 2ea7742..40980af 100644
--- a/src/common/serverstate.rs
+++ b/src/common/serverstate.rs
@@ -23,6 +23,7 @@ pub trait ServerState {
     type PacketError;
     
     fn on_connect(&mut self, id: ClientId) -> Vec<OnConnect<Self::SendPacket>>;
-    fn handle(&mut self, id: ClientId, pkt: &Self::RecvPacket) -> Box<dyn Iterator<Item = (ClientId, Self::SendPacket)>>;
+    fn handle(&mut self, id: ClientId, pkt: &Self::RecvPacket)
+              -> Result<Box<dyn Iterator<Item = (ClientId, Self::SendPacket)>>, Self::PacketError>;
 }
 
diff --git a/src/login/login.rs b/src/login/login.rs
index c157ad8..d5c98a8 100644
--- a/src/login/login.rs
+++ b/src/login/login.rs
@@ -133,8 +133,9 @@ impl<DA: DataAccess> ServerState for LoginServerState<DA> {
         ]
     }
 
-    fn handle(&mut self, id: ClientId, pkt: &Self::RecvPacket) -> Box<dyn Iterator<Item = (ClientId, Self::SendPacket)>> {
-        match pkt {
+    fn handle(&mut self, id: ClientId, pkt: &Self::RecvPacket)
+              -> Result<Box<dyn Iterator<Item = (ClientId, Self::SendPacket)>>, LoginError> {
+        Ok(match pkt {
             RecvLoginPacket::Login(login) => {
                 Box::new(self.validate_login(login)
                          .into_iter()
@@ -142,7 +143,7 @@ impl<DA: DataAccess> ServerState for LoginServerState<DA> {
                              (id, pkt)
                          }))
             }
-        }
+        })
     }
 }
 
diff --git a/src/patch/main.rs b/src/patch/main.rs
index 39b52d8..b15df0b 100644
--- a/src/patch/main.rs
+++ b/src/patch/main.rs
@@ -180,8 +180,9 @@ impl ServerState for PatchServerState {
         ]
     }
 
-    fn handle(&mut self, id: ClientId, pkt: &RecvPatchPacket) -> Box<dyn Iterator<Item = (ClientId, SendPatchPacket)>> {
-        match pkt {
+    fn handle(&mut self, id: ClientId, pkt: &RecvPatchPacket)
+              -> Result<Box<dyn Iterator<Item = (ClientId, SendPatchPacket)>>, PatchError> {
+        Ok(match pkt {
             RecvPatchPacket::PatchWelcomeReply(_pkt) => {
                 Box::new(vec![SendPatchPacket::RequestLogin(RequestLogin {})].into_iter().map(move |pkt| (id, pkt)))
             },
@@ -208,7 +209,7 @@ impl ServerState for PatchServerState {
                 ];
                 Box::new(p.into_iter().chain(SendFileIterator::new(&self)).map(move |pkt| (id, pkt)))
             }
-        }
+        })
     }
 }