diff --git a/lib/pages/lobby_selector.dart b/lib/pages/lobby_selector.dart
index 67f38aa..9748407 100644
--- a/lib/pages/lobby_selector.dart
+++ b/lib/pages/lobby_selector.dart
@@ -1,5 +1,6 @@
 import 'dart:convert';
 import 'dart:developer';
+import 'dart:io';
 
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
@@ -91,34 +92,41 @@ class _LobbySelectorState extends State<LobbySelector> {
     return showDialog<void>(
       context: context,
       builder: (BuildContext context) {
-        return AlertDialog(
-          title: const Text('Enter the passphrase here:'),
-          content: TextField(
-            controller: phraseController,
-            decoration: InputDecoration(
-                hintText: 'Enter passphrase here',
-                suffixIcon: IconButton(
-                  onPressed: () {
-                    joinGameFuture = joinPrivateGame();
-                    joinGameFuture.then((value) {
-                      if (value != null) {
-                        phraseController.clear();
-                        context.pop();
-                        switchToGame(value);
-                      }
-                    });
-                  },
-                  icon: const Icon(Icons.check),
-                )),
-          ),
-          actions: <Widget>[
-            TextButton(
-              child: const Text('Cancel'),
-              onPressed: () {
-                context.pop();
-              },
-            ),
-          ],
+        return ScaffoldMessenger(
+          child: Builder(builder: (builderContext) {
+            return Scaffold(
+              backgroundColor: Colors.transparent,
+              body: AlertDialog(
+                title: const Text('Enter the passphrase here:'),
+                content: TextField(
+                  controller: phraseController,
+                  decoration: InputDecoration(
+                      hintText: 'Enter passphrase here',
+                      suffixIcon: IconButton(
+                        onPressed: () {
+                          joinGameFuture = joinPrivateGame(builderContext);
+                          joinGameFuture.then((value) {
+                            if (value != null) {
+                              phraseController.clear();
+                              builderContext.pop();
+                              switchToGame(value);
+                            }
+                          });
+                        },
+                        icon: const Icon(Icons.check),
+                      )),
+                ),
+                actions: <Widget>[
+                  TextButton(
+                    child: const Text('Cancel'),
+                    onPressed: () {
+                      builderContext.pop();
+                    },
+                  ),
+                ],
+              ),
+            );
+          }),
         );
       },
     );
@@ -144,12 +152,14 @@ class _LobbySelectorState extends State<LobbySelector> {
       );
       ScaffoldMessenger.of(context).clearSnackBars();
       ScaffoldMessenger.of(context).showSnackBar(snackBar);
+
+      return;
     }
 
     context.goNamed('game', extra: chessGameArgs);
   }
 
-  Future<PlayerInfo?> joinPrivateGame() async {
+  Future<PlayerInfo?> joinPrivateGame(BuildContext context) async {
     http.Response response;
 
     // server expects us to send the passphrase
@@ -168,14 +178,25 @@ class _LobbySelectorState extends State<LobbySelector> {
         backgroundColor: Colors.amberAccent,
         content: Text("mChess server is not responding. Try again or give up"),
       );
-      if (mounted) {
-        ScaffoldMessenger.of(context).clearSnackBars();
-        ScaffoldMessenger.of(context).showSnackBar(snackBar);
-      }
+      ScaffoldMessenger.of(context).clearSnackBars();
+      ScaffoldMessenger.of(context).showSnackBar(snackBar);
       return null;
     }
 
-    if (response.statusCode == 200) {
+    if (response.statusCode == HttpStatus.notFound) {
+      const snackBar = SnackBar(
+        backgroundColor: Colors.amberAccent,
+        content: Text("Passphrase could not be found."),
+      );
+
+      if (!context.mounted) return null;
+
+      ScaffoldMessenger.of(context).clearSnackBars();
+      ScaffoldMessenger.of(context).showSnackBar(snackBar);
+      return null;
+    }
+
+    if (response.statusCode == HttpStatus.ok) {
       var info = PlayerInfo.fromJson(jsonDecode(response.body));
       log('Player info received from server: ');
       log('lobbyID: ${info.lobbyID}');
diff --git a/lib/utils/config.dart b/lib/utils/config.dart
index ca484a0..863dedb 100644
--- a/lib/utils/config.dart
+++ b/lib/utils/config.dart
@@ -1,12 +1,12 @@
 const prodURL = 'chess.sw-gross.de:9999';
 const debugURL = 'localhost:8080';
 
-const dbgUrl = false;
+const useDbgUrl = false;
 
 String getHostURL() {
   var prot = 'https';
   var domain = prodURL;
-  if (dbgUrl) {
+  if (useDbgUrl) {
     prot = 'http';
     domain = debugURL;
   }
@@ -16,7 +16,7 @@ String getHostURL() {
 String getJoinURL() {
   var prot = 'https';
   var domain = prodURL;
-  if (dbgUrl) {
+  if (useDbgUrl) {
     prot = 'http';
     domain = debugURL;
   }
@@ -26,7 +26,7 @@ String getJoinURL() {
 String getWebsocketURL() {
   var prot = 'wss';
   var domain = prodURL;
-  if (dbgUrl) {
+  if (useDbgUrl) {
     prot = 'ws';
     domain = debugURL;
   }