diff --git a/api/batch.py b/api/batch.py
index 44a24a0..1595339 100644
--- a/api/batch.py
+++ b/api/batch.py
@@ -13,16 +13,16 @@ async def batch_handler(request: Request):
     token = data.get("token")
     platform = data.get("platform")
     if not token:
-        return HTMLResponse(content=json.dumps({"error": "Token is required"}), status_code=400)
+        return HTMLResponse(content="Token is required", status_code=400)
     
     if platform not in ["Android", "iOS"]:
-        return HTMLResponse(content=json.dumps({"error": "Invalid platform"}), status_code=400)
-    
+        return HTMLResponse(content="Invalid platform", status_code=400)
+
     query = batch_token.select().where(batch_token.c.token == token)
     result = await database.fetch_one(query)
 
     if result['expire_at'] < int(time.time()):
-        return HTMLResponse(content=json.dumps({"error": "Token expired"}), status_code=400)
+        return HTMLResponse(content="Token expired", status_code=400)
     
     with open(os.path.join('api/config/', 'download_manifest.json'), 'r', encoding='utf-8') as f:
             stage_manifest = json.load(f)
diff --git a/various-tools/Asset preloading flutter app/server_checker/lib/main.dart b/various-tools/Asset preloading flutter app/server_checker/lib/main.dart
index 663cb27..6c37367 100644
--- a/various-tools/Asset preloading flutter app/server_checker/lib/main.dart	
+++ b/various-tools/Asset preloading flutter app/server_checker/lib/main.dart	
@@ -49,6 +49,10 @@ class _HomeScreenState extends State<HomeScreen> {
   Future<void> initBatch(String serverUrl, String token) async {
     setState(() => _result = "Checking...");
 
+    if (serverUrl.endsWith("/")) {
+      serverUrl = serverUrl.substring(0, serverUrl.length - 1);
+    }
+
     try {
       final url = Uri.parse('$serverUrl/batch');
       final payload = {
@@ -71,7 +75,7 @@ class _HomeScreenState extends State<HomeScreen> {
             context,
             MaterialPageRoute(
               builder: (_) => DownloadScreen(
-                files: data["stage"] ?? {},
+                files: Map<String, int>.from(data["stage"] ?? {}),
                 threadCount: data["thread"] ?? 1,
                 title: "Downloading Stages",
                 serverUrl: serverUrl,
@@ -83,7 +87,7 @@ class _HomeScreenState extends State<HomeScreen> {
             context,
             MaterialPageRoute(
               builder: (_) => DownloadScreen(
-                files: data["audio"] ?? {},
+                files: Map<String, int>.from(data["audio"] ?? {}),
                 threadCount: data["thread"] ?? 1,
                 title: "Downloading Music",
                 serverUrl: serverUrl,
@@ -96,7 +100,10 @@ class _HomeScreenState extends State<HomeScreen> {
           );
         }
       } else {
-        setState(() => _result = "Server error: ${response.statusCode}");
+        setState(
+          () => _result =
+              "Server error: ${response.statusCode}, ${response.body}",
+        );
       }
     } catch (e) {
       setState(() => _result = "Request failed: $e");
diff --git a/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk b/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk
index 1b71203..0a693df 100644
Binary files a/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk and b/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk differ
diff --git a/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk.sha1 b/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk.sha1
index 6ea4d76..d898083 100644
--- a/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk.sha1	
+++ b/various-tools/Asset preloading flutter app/server_checker/pre-built/app-release.apk.sha1	
@@ -1 +1 @@
-07e3ccb23568eac4c695ea7c08e5679f3c696ac5
\ No newline at end of file
+7a8131d9aa79e42356d6df84508d44f230a6df95
\ No newline at end of file