diff --git a/qr2/challenge.go b/qr2/challenge.go
index 311cb28..f753d35 100644
--- a/qr2/challenge.go
+++ b/qr2/challenge.go
@@ -7,6 +7,9 @@ import (
 	"strings"
 	"time"
 	"wwfc/common"
+	"wwfc/logging"
+
+	"github.com/logrusorgru/aurora/v3"
 )
 
 func sendChallenge(conn net.PacketConn, addr net.UDPAddr, session Session, lookupAddr uint64) {
@@ -47,11 +50,15 @@ func sendChallenge(conn net.PacketConn, addr net.UDPAddr, session Session, looku
 	response = append(response, 0)
 
 	go func() {
-		for {
-			conn.WriteTo(response, &addr)
+		for i := 0; i < 5; i++ {
+			_, err := conn.WriteTo(response, &addr)
 
 			time.Sleep(1 * time.Second)
 
+			if err != nil {
+				continue
+			}
+
 			mutex.Lock()
 			session, ok := sessions[lookupAddr]
 			if !ok || session.Authenticated || session.LastKeepAlive < time.Now().UTC().Unix()-60 {
@@ -61,5 +68,9 @@ func sendChallenge(conn net.PacketConn, addr net.UDPAddr, session Session, looku
 			addr = session.Addr
 			mutex.Unlock()
 		}
+		logging.Info("QR2", "Failed to send challenge to", aurora.Cyan(addr.String()))
+		mutex.Lock()
+		defer mutex.Unlock()
+		removeSession(lookupAddr)
 	}()
 }
diff --git a/qr2/group.go b/qr2/group.go
index 0d0c93d..251d046 100644
--- a/qr2/group.go
+++ b/qr2/group.go
@@ -139,6 +139,7 @@ func processResvOK(moduleName string, matchVersion int, reservation common.Match
 }
 
 func processTellAddr(moduleName string, sender *Session, destination *Session) {
+	common.MaybeUnused(moduleName)
 	if sender.groupPointer != nil && sender.groupPointer == destination.groupPointer {
 		// Just assume the connection is successful if TELL_ADDR is used
 		sender.Data["+conn_"+destination.Data["+joinindex"]] = "2"
@@ -264,6 +265,8 @@ func ProcessGPStatusUpdate(profileID uint32, senderIP uint64, status string) {
 }
 
 func checkReservationAllowed(moduleName string, sender, destination *Session, joinType byte) string {
+	common.MaybeUnused(moduleName)
+
 	if sender.login == nil || destination.login == nil {
 		return ""
 	}
@@ -602,11 +605,12 @@ func saveGroups() error {
 	if err != nil {
 		return err
 	}
+	defer func() {
+		common.ShouldNotError(file.Close())
+	}()
 
 	encoder := gob.NewEncoder(file)
-	err = encoder.Encode(groups)
-	file.Close()
-	return err
+	return encoder.Encode(groups)
 }
 
 // loadGroups loads the groups state from disk.
@@ -616,10 +620,12 @@ func loadGroups() error {
 	if err != nil {
 		return err
 	}
+	defer func() {
+		common.ShouldNotError(file.Close())
+	}()
 
 	decoder := gob.NewDecoder(file)
 	err = decoder.Decode(&groups)
-	file.Close()
 	if err != nil {
 		return err
 	}
diff --git a/qr2/group_info.go b/qr2/group_info.go
index 954c97f..a6b36ec 100644
--- a/qr2/group_info.go
+++ b/qr2/group_info.go
@@ -77,11 +77,12 @@ func getGroupsRaw(gameNames []string, groupNames []string) []GroupInfo {
 			SortedJoinIndex: []string{},
 		}
 
-		if group.MatchType == "0" || group.MatchType == "1" {
+		switch group.MatchType {
+		case "0", "1":
 			groupInfo.MatchType = "anybody"
-		} else if group.MatchType == "2" || group.MatchType == "3" {
+		case "2", "3":
 			groupInfo.MatchType = "private"
-		} else {
+		default:
 			groupInfo.MatchType = "unknown"
 		}
 
diff --git a/qr2/logins.go b/qr2/logins.go
index a5f3157..c187475 100644
--- a/qr2/logins.go
+++ b/qr2/logins.go
@@ -4,6 +4,7 @@ import (
 	"encoding/gob"
 	"os"
 	"strconv"
+	"wwfc/common"
 )
 
 type LoginInfo struct {
@@ -71,11 +72,12 @@ func saveLogins() error {
 	if err != nil {
 		return err
 	}
+	defer func() {
+		common.ShouldNotError(file.Close())
+	}()
 
 	encoder := gob.NewEncoder(file)
-	err = encoder.Encode(logins)
-	file.Close()
-	return err
+	return encoder.Encode(logins)
 }
 
 // Load logins from a file. Expects the mutex to be locked, and the sessions to already be loaded.
@@ -84,10 +86,12 @@ func loadLogins() error {
 	if err != nil {
 		return err
 	}
+	defer func() {
+		common.ShouldNotError(file.Close())
+	}()
 
 	decoder := gob.NewDecoder(file)
 	err = decoder.Decode(&logins)
-	file.Close()
 	if err != nil {
 		return err
 	}
diff --git a/qr2/main.go b/qr2/main.go
index f8ebc8a..fda4a7d 100644
--- a/qr2/main.go
+++ b/qr2/main.go
@@ -92,7 +92,9 @@ func StartServer(reload bool) {
 		defer waitGroup.Done()
 
 		// Close the listener when the application closes.
-		defer conn.Close()
+		defer func() {
+			common.ShouldNotError(conn.Close())
+		}()
 		logging.Notice("QR2", "Listening on", aurora.BrightCyan(address))
 
 		for {
@@ -115,7 +117,7 @@ func StartServer(reload bool) {
 
 func Shutdown() {
 	inShutdown.SetTrue()
-	masterConn.Close()
+	common.ShouldNotError(masterConn.Close())
 	waitGroup.Wait()
 
 	mutex.Lock()
@@ -179,7 +181,7 @@ func handleConnection(conn net.PacketConn, addr net.UDPAddr, buffer []byte) {
 			session.Authenticated = true
 			mutex.Unlock()
 
-			conn.WriteTo(createResponseHeader(ClientRegisteredReply, session.SessionID), &addr)
+			_, _ = conn.WriteTo(createResponseHeader(ClientRegisteredReply, session.SessionID), &addr)
 		} else {
 			mutex.Unlock()
 		}
@@ -216,14 +218,14 @@ func handleConnection(conn net.PacketConn, addr net.UDPAddr, buffer []byte) {
 
 	case KeepAliveRequest:
 		// logging.Info(moduleName, "Command:", aurora.Yellow("KEEPALIVE"))
-		conn.WriteTo(createResponseHeader(KeepAliveRequest, 0), &addr)
+		_, _ = conn.WriteTo(createResponseHeader(KeepAliveRequest, 0), &addr)
 
 		session.LastKeepAlive = time.Now().UTC().Unix()
 		return
 
 	case AvailableRequest:
 		logging.Info("QR2", "Command:", aurora.Yellow("AVAILABLE"))
-		conn.WriteTo(createResponseHeader(AvailableRequest, 0), &addr)
+		_, _ = conn.WriteTo(createResponseHeader(AvailableRequest, 0), &addr)
 		return
 
 	case ClientRegisteredReply:
diff --git a/qr2/message.go b/qr2/message.go
index 99e5878..9d191df 100644
--- a/qr2/message.go
+++ b/qr2/message.go
@@ -314,7 +314,8 @@ func processClientMessage(moduleName string, sender, receiver *Session, message
 	cmd := message[8]
 	common.LogMatchCommand(moduleName, destPid, cmd, matchData)
 
-	if cmd == common.MatchReservation {
+	switch cmd {
+	case common.MatchReservation:
 		resvError := checkReservationAllowed(moduleName, sender, receiver, matchData.Reservation.MatchType)
 		if resvError != "ok" {
 			if resvError == "restricted" || resvError == "restricted_join" {
@@ -340,7 +341,8 @@ func processClientMessage(moduleName string, sender, receiver *Session, message
 
 		sender.Reservation = matchData
 		sender.ReservationID = receiver.SearchID
-	} else if cmd == common.MatchResvOK || cmd == common.MatchResvDeny || cmd == common.MatchResvWait {
+
+	case common.MatchResvOK, common.MatchResvDeny, common.MatchResvWait:
 		if receiver.ReservationID != sender.SearchID || receiver.Reservation.Reservation == nil {
 			logging.Warn(moduleName, "Destination has no reservation with the sender")
 			if receiver.groupPointer == nil || receiver.groupPointer != sender.groupPointer {
@@ -361,7 +363,8 @@ func processClientMessage(moduleName string, sender, receiver *Session, message
 		} else if receiver.ReservationID == sender.SearchID {
 			receiver.ReservationID = 0
 		}
-	} else if cmd == common.MatchTellAddr {
+
+	case common.MatchTellAddr:
 		processTellAddr(moduleName, sender, receiver)
 	}
 
diff --git a/qr2/session.go b/qr2/session.go
index 272f7e5..c179138 100644
--- a/qr2/session.go
+++ b/qr2/session.go
@@ -315,11 +315,12 @@ func saveSessions() error {
 	if err != nil {
 		return err
 	}
+	defer func() {
+		common.ShouldNotError(file.Close())
+	}()
 
 	encoder := gob.NewEncoder(file)
-	err = encoder.Encode(sessions)
-	file.Close()
-	return err
+	return encoder.Encode(sessions)
 }
 
 // Load the sessions from a file. Expects the mutex to be locked.
@@ -328,10 +329,12 @@ func loadSessions() error {
 	if err != nil {
 		return err
 	}
+	defer func() {
+		common.ShouldNotError(file.Close())
+	}()
 
 	decoder := gob.NewDecoder(file)
 	err = decoder.Decode(&sessions)
-	file.Close()
 	if err != nil {
 		return err
 	}