How can I debug an Apple Enterprise Deployment by manifest?

Question

I'm trying to deploy an app thorough a manifest file. After clicking on button in Safari, nothing happens, no error, just loading. My manifest looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <!-- Array der Downloads. -->
  <key>items</key>
  <array>
   <dict>
    <!-- Array der zu ladenden Ressourcen -->
     <key>assets</key>
      <array>
       <!-- Softwarepaket: die zu installierende ipa-Datei. -->
        <dict>
         <!-- Pflicht: die Art der Ressource. -->
          <key>kind</key>
          <string>software-package</string>
          <!-- Pflicht: die URL der zu ladenden Datei. -->
          <key>url</key>
          <string>%url%</string>
        </dict>
      </array><key>metadata</key>
      <dict>
       <!-- Pflicht -->
       <key>bundle-identifier</key>
       <string>%bundleIdentifier%</string>
       <key>bundle-version</key>
       <string>%bundleVersion%</string>
       <!-- Pflicht: die Art des Downloads. -->
       <key>kind</key>
       <string>software</string>
       <!-- Pflicht: der beim Download anzuzeigende Titel. -->
       <key>title</key>
       <string>%title%</string>
      </dict>
    </dict>
  </array>
</dict>
</plist>

EDIT 1

My link looks like this:

<a href="itms-services://?action=download-manifest&amp;url=https://someSite.de/applications/557170c4ffcb521300cacb59/versions/557170e7ffcb521300cacb5a/manifest.plist?access_token=g3hf32v8h5bfeg4t50zfepwzrb9w8b3rv9382va0we7352635baivo" target="_blank" translate="INSTALL" class="ng-scope">Installieren</a>

EDIT 2

This is one of my plists:

<plist version="1.0">
<dict>
<!--  Array der Downloads.  -->
<key>items</key>
<array>
<dict>
<!--  Array der zu ladenden Ressourcen  -->
<key>assets</key>
<array>
<!--  Softwarepaket: die zu installierende ipa-Datei.  -->
<dict>
<!--  Pflicht: die Art der Ressource.  -->
<key>kind</key>
<string>software-package</string>
<!--  Pflicht: die URL der zu ladenden Datei.  -->
<key>url</key>
<string>
https://someSite.de/applications/557170c4ffcb521300cacb59/versions/557170e7ffcb521300cacb5a/app.ipa?access_token=g3hf32v8h5bfeg4t50zfepwzrb9w8b3rv9382va0we7352635baivo
</string>
</dict>
</array>
<key>metadata</key>
<dict>
<!--  Pflicht  -->
<key>bundle-identifier</key>
<string>com.someSite</string>
<key>bundle-version</key>
<string>0.0.1</string>
<!--  Pflicht: die Art des Downloads.  -->
<key>kind</key>
<string>software</string>
<!--  Pflicht: der beim Download anzuzeigende Titel.  -->
<key>title</key>
<string>MyApp</string>
</dict>
</dict>
</array>
</dict>
</plist>

Answer 1

Two steps, that fixed the issue: 1. Specify a display-image 2. Encode manifest-url: e.g.

<a href="itms-services://?action=download-manifest&amp;url=https%3A%2F%2FsomeSite.de%2Fapplications%2F557170c4ffcb521300cacb59%2Fversions%2F557170e7ffcb521300cacb5a%2Fmanifest.plist%3Faccess_token%3Dg3hf32v8h5bfeg4t50zfepwzrb9w8b3rv9382va0we7352635baivo" target="_blank" translate="INSTALL" class="ng-scope">Installieren</a>