Error if deleting a webdav user

Running (Debian Bookworm) ISPConfig 3.2.12p1
PHP Fatal error: Uncaught TypeError: fgets(): Argument #1 ($stream) must be of type resource, bool given in /usr/local/ispconfig/server/plugins-available/apache2_plugin.inc.php:2990

I deleted the section, and the call to patchVhostWebdav, else the jobshandeling get stuc.

/**
* This function patches the vhost-file and adds all webdav - user.
* This function is written, because the creation of the vhost - file is sophisticated and
* i don't want to make it more "heavy" by also adding this code too...
* @author Oliver Vogel
* @param string $fileName The Name of the .vhost-File (path included)
* @param string $webdavRoot The root of the webdav-folder
*/
private function _patchVhostWebdav($fileName, $webdavRoot) {
global $app;
$in = fopen($fileName, 'r');
$output = '';
$inWebdavSection = false;
/*
* read line by line and search for the username and authname
*/
while ($line = fgets($in)) {
/*
* is the "replace-comment" found...
*/
if (trim($line) == '# WEBDAV BEGIN') {
/*
* The begin of the webdav - section is found, so ignore all lines til the end is found
*/
$inWebdavSection = true;
$output .= " # WEBDAV BEGIN\n";
/*
* add all the webdav-dirs to the webdav-section
*/
$files = @scandir($webdavRoot);
if(is_array($files)) {
foreach($files as $file) {
if (substr($file, strlen($file) - strlen('.htdigest')) == '.htdigest' && preg_match("/^[a-zA-Z0-9\-_\.]*$/", $file)) {
/*
* found a htdigest - file, so add it to webdav
*/
$fn = substr($file, 0, strlen($file) - strlen('.htdigest'));
$output .= "\n";
// $output .= " Alias /" . $fn . ' ' . $webdavRoot . '/' . $fn . "\n";
// $output .= " <Location /" . $fn . ">\n";
$output .= " Alias /webdav/" . $fn . ' ' . $webdavRoot . '/' . $fn . "\n";
$output .= " <Location /webdav/" . $fn . ">\n";
$output .= " DAV On\n";
$output .= ' BrowserMatch "MSIE" AuthDigestEnableQueryStringHack=On'."\n";
$output .= " AuthType Digest\n";
if($fn != '' && $fn != '/') {
$output .= " AuthName \"" . $fn . "\"\n";
} else {
$output .= " AuthName \"Restricted Area\"\n";
}
$output .= " AuthUserFile " . $webdavRoot . '/' . $file . "\n";
$output .= " Require valid-user \n";
$output .= " Options +Indexes \n";
$output .= " Order allow,deny \n";
$output .= " Allow from all \n";
$output .= " </Location> \n";
}
}
}
}
/*
* is the "replace-comment-end" found...
*/
if (trim($line) == '# WEBDAV END') {
/*
* The end of the webdav - section is found, so stop ignoring
*/
$inWebdavSection = false;
}
/*
* Write the line to the output, if it is not in the section
*/
if (!$inWebdavSection) {
$output .= $line;
}
}
fclose($in);
/*
* Now lets write the new file
*/
$app->system->file_put_contents($fileName, $output);
}