diff --git a/build-plugin.sh b/build-plugin.sh
index da35fd4..d991b9a 100755
--- a/build-plugin.sh
+++ b/build-plugin.sh
@@ -2,7 +2,7 @@
 set -eu
 
 PLUGIN="u-navigator"
-VERSION="2026.06.23.r046"
+VERSION="2026.06.23.r047"
 PKG_DIR="packages"
 WORK_DIR=".plugin-build"
 PKG_NAME="${PLUGIN}-${VERSION}.tgz"
diff --git a/packages/u-navigator-2026.06.23.r046.tgz b/packages/u-navigator-2026.06.23.r046.tgz
deleted file mode 100644
index 3fd68bc..0000000
Binary files a/packages/u-navigator-2026.06.23.r046.tgz and /dev/null differ
diff --git a/packages/u-navigator-2026.06.23.r047.tgz b/packages/u-navigator-2026.06.23.r047.tgz
new file mode 100644
index 0000000..5d302cf
Binary files /dev/null and b/packages/u-navigator-2026.06.23.r047.tgz differ
diff --git a/plugin-root/usr/local/emhttp/plugins/u-navigator/api/upload.php b/plugin-root/usr/local/emhttp/plugins/u-navigator/api/upload.php
index fe60f78..acc6832 100644
--- a/plugin-root/usr/local/emhttp/plugins/u-navigator/api/upload.php
+++ b/plugin-root/usr/local/emhttp/plugins/u-navigator/api/upload.php
@@ -10,24 +10,14 @@ if (!is_dir($target['path'])) {
 if (isset($_GET['relativePath']) || isset($_SERVER['HTTP_X_UNAV_RELATIVE_PATH'])) {
     $relativeName = (string)($_GET['relativePath'] ?? $_SERVER['HTTP_X_UNAV_RELATIVE_PATH']);
     $destination = unav_prepare_upload_destination($target['path'], $relativeName);
-    $input = fopen('php://input', 'rb');
-    $output = fopen($destination['path'], 'xb');
-    if (!$input || !$output) {
-        if ($input) {
-            fclose($input);
-        }
-        if ($output) {
-            fclose($output);
-        }
-        unav_error(500, 'Could not open upload stream');
+    $bytes = file_put_contents($destination['path'], file_get_contents('php://input'), LOCK_EX);
+    if ($bytes === false) {
+        unav_error(500, 'Could not store uploaded file');
     }
-    stream_copy_to_stream($input, $output);
-    fclose($input);
-    fclose($output);
     unav_json([
         'uploaded' => [[
             'name' => $destination['relative'],
-            'size' => filesize($destination['path']) ?: 0,
+            'size' => $bytes,
         ]],
     ], 201);
 }
diff --git a/server/public/app.js b/server/public/app.js
index 5cfd2e0..c29d2cd 100644
--- a/server/public/app.js
+++ b/server/public/app.js
@@ -915,11 +915,31 @@ async function uploadFileList(win, files, targetPath) {
     } else {
       recordDebug('csrf.missing', {});
     }
-    await fetchChecked(apiUrl(`upload.php?${params.toString()}`), {
+    const response = await fetch(apiUrl(`upload.php?${params.toString()}`), {
       method: 'POST',
       headers: { 'Content-Type': 'application/octet-stream' },
       body: item.file
     });
+    const text = await response.text();
+    recordDebug('upload.file.response', {
+      path: item.path,
+      status: response.status,
+      ok: response.ok,
+      contentType: response.headers.get('content-type'),
+      body: text.slice(0, 1000)
+    });
+    if (!response.ok) {
+      throw new Error(text || `${response.status} ${response.statusText}`);
+    }
+    let payload;
+    try {
+      payload = JSON.parse(text);
+    } catch (error) {
+      throw new Error(`Upload lieferte keine JSON-Antwort: ${text.slice(0, 200) || response.headers.get('content-type') || 'leer'}`);
+    }
+    if (!payload.uploaded?.length) {
+      throw new Error('Upload wurde vom Server nicht bestätigt.');
+    }
     recordDebug('upload.file.done', { path: item.path, index: index + 1, total: uploadItems.length });
   }
   await loadExplorer(win, targetPath);
diff --git a/u-navigator.plg b/u-navigator.plg
index 030e657..e48cdde 100644
--- a/u-navigator.plg
+++ b/u-navigator.plg
@@ -1,7 +1,7 @@
 <!DOCTYPE PLUGIN [
 <!ENTITY name "u-navigator">
 <!ENTITY author "Michael Roll">
-<!ENTITY version "2026.06.23.r046">
+<!ENTITY version "2026.06.23.r047">
 <!ENTITY package "&name;-&version;.tgz">
 <!ENTITY pluginURL "https://git.casaderoll.de/michael/Unraid-Navigator/raw/branch/main/u-navigator.plg">
 <!ENTITY support "https://git.casaderoll.de/michael/Unraid-Navigator">
@@ -24,7 +24,7 @@
 
 <FILE Name="/boot/config/plugins/&name;/&package;">
 <URL>https://git.casaderoll.de/michael/Unraid-Navigator/raw/branch/main/packages/&package;</URL>
-<MD5>acb81bdc26294c48b2115013cac89015</MD5>
+<MD5>3c9e5a641720371ec7cee8bd70a32d8e</MD5>
 </FILE>
 
 <FILE Run="/bin/bash">