Problems with WordPress app

Thanks for posting; unfortunately, I’m not sure how to solve this issue – I suggest trial and error until you figure it out.

A couple suggestions though:

1. In your whitelist code, if you’re not going to use the site_url() function to get the site address; then remove the parenthesis too. For example:

function my_forcelogin_whitelist( $whitelist ) {
  $whitelist[] = 'http://www.viplosjen.no/xmlrpc.php';
  $whitelist[] = 'http://viplosjen.no/xmlrpc.php';
  return $whitelist;
}
add_filter('v_forcelogin_whitelist', 'my_forcelogin_whitelist', 10, 1);

2. I googled your error message and found the following results that might be helpful to you figuring out this issue:

https://ww.wp.xz.cn/support/topic/jetpack-publicize-error-message
https://ios.forums.ww.wp.xz.cn/topic/jetpack-is-return-error

3. One more option you could try for whitelisting the xmlrpc.php page, is to whitelist it regardless of a query string? For example:

/**
 * Filter Force Login to allow exceptions for specific URLs.
 *
 * @return array An array of URLs. Must be absolute.
 **/
function my_forcelogin_whitelist( $whitelist ) {
  // Get visited URL without query string
  $url_path = preg_replace('/\?.*/', '', $_SERVER['REQUEST_URI']);

  // Whitelist URLs
  if( '/xmlrpc.php' === $url_path ) {
    $whitelist[] = site_url($_SERVER['REQUEST_URI']);
  }
  return $whitelist;
}
add_filter('v_forcelogin_whitelist', 'my_forcelogin_whitelist', 10, 1);

Great! Glad we were able to solve your issue.

Be sure to rate and review my plugin to let others know how you like it; enjoy!