title: TYPO3 GeneralUtility Class 0; not found (own generic extension)
body: <p>After creating my own Extension with the ExtensionBuilder-Package and activating it, I created a repository for the data and set the Storage-PID in the Template-Constants.</p>
  <p>Then I created a new page containing the extension (with default values) and on viewing the page the following error appears and the page does not show:</p>
  <pre><code>Core: Exception handler (WEB): Uncaught TYPO3 Exception: Class '0;' not found | Error thrown in file /var/www/html/typo3Insy/public/typo3/sysext/core/Classes/Utility/GeneralUtility.php
  </code></pre>
  <p><em>For the setup I used the TYPO3 version 9.5.23 and have not migrated from a previous one.</em></p>