We are currently facing issues with TYPO3 8.4.1 while saving files within the "Text & Media" content element, especially youtube or vimeo elements. We deploy our application with Surf, so we have the Surf folder structure. TYPO3 uses the _TYPO3\CMS\Core\Utility\GeneralUtility::writeFileToTypo3tempDir()_ `TYPO3\CMS\Core\Utility\GeneralUtility::writeFileToTypo3tempDir()` method to write the file temporary to the _typo3temp_ `typo3temp` directory. But during the execution of the method, it compares two paths pointing to the file, that cannot be conform: _/var/www/releases/current/web/fileadmin/..._ `/var/www/releases/current/web/fileadmin/...` with _/var/www/releases/20161215160349/web/fileadmin/..._. `/var/www/releases/20161215160349/web/fileadmin/...`. As result the file is not correctly written and empty, and TYPO3 cannot handle it. The content element is created anyway without an error message, the related file is missing.