Warn about possibly invalid map names

RLBotCS/Conversion/FlatToCommand.cs

@@ -406,7 +406,21 @@ public static (string, CustomMap?) MakeOpenCommand(MatchConfigurationT matchConf
             }
             else
             {
-                command += matchConfig.GameMapUpk;
+                // Warn if the map name doesn't look like a valid official or custom map.
+                // Official maps end with _p or _P, custom maps end with .upk or .udk.
+                string mapUpk = matchConfig.GameMapUpk;
+                bool isOfficialMap = mapUpk.EndsWith("_p", StringComparison.OrdinalIgnoreCase);
+                bool isCustomMapExtension =
+                    mapUpk.EndsWith(".upk", StringComparison.OrdinalIgnoreCase)
+                    || mapUpk.EndsWith(".udk", StringComparison.OrdinalIgnoreCase);
+                if (!isOfficialMap && !isCustomMapExtension)
+                {
+                    Logger.LogWarning(
+                        $"Map name '{mapUpk}' does not end with '_p'/'_P' (official maps) or '.upk'/'.udk' (custom maps). "
+                            + "The map may fail to load. Official map names should end with '_p', e.g. 'Stadium_P'."
+                    );
+                }
+                command += mapUpk;
             }
         }
         else

RLBotCS/Server/FlatBuffersServer.cs

@@ -84,7 +84,7 @@ private async Task HandleIncomingMessages()
             }
     }
 
-    private async Task HandleServer()
+ private async Task HandleServer()
     {
         try
         {
@@ -105,6 +105,18 @@ private async Task HandleServer()
                 }
             }
         }
+        catch (SocketException e) when (e.SocketErrorCode == SocketError.AddressAlreadyInUse)
+        {
+            _context.Logger.LogError(
+                $"Port {rlbotPort} is already in use. Is another instance of RLBot already running?"
+            );
+        }
+        catch (SocketException e) when (e.SocketErrorCode == SocketError.OperationAborted)
+        {
+            // This happens during normal shutdown when the server is stopped while waiting
+            // for a connection. Not an error.
+            _context.Logger.LogDebug("Server stopped while waiting for connections.");
+        }
         catch (Exception e)
         {
             _context.Logger.LogError($"Error while handling server: {e}");