Piwigo plugins and themes access

The message "Connection to server unavailable" is correct. The PHP code needs to retrieve information from piwigo.org, but the outgoing request seems to get blocked, or the response cannot get back. It could also be a DNS problem.

I put in some extra messages to appear in the browser inside /apps/piwigo/web/admin/include/functions.php

  echo "<br>TRY TO READ FROM SOCKET: $host$path";
  if (($s = @fsockopen($host,80,$errno,$errstr,5)) === false)
  {
    echo "<br>errno: $errno";
    echo "<br>errstr: $errstr";
    echo "<br>UNABLE TO READ FROM SOCKET";
    return false;
  }

This is the result:

TRY TO READ FROM SOCKET: piwigo.org/ext/api/get_version_list.php?category_id=10&format=php
errno: 113
errstr: No route to host
UNABLE TO READ FROM SOCKET

My guess is that when PHP issues the request towards piwigo.org, the response gets blocked on its way back to the NAS. Or the request is already blocked going out of the intranet by the NAS firewall, by the internet router or inside the ISP network. Not sure how to solve this, as this can have many causes.

With my browser I can read the content of the URL http://piwigo.org/ext/api/get_version_list.php?category_id=10&format=php. It displays:

a:50:{i:0;a:3:{s:2:"id";s:2:"76";s:4:"name";s:3:"2.6";s:13:"nb_extensions";s:2:"39";}i:1;a:3:{s:2:"id";s:2:"75";s:4:"name";s:3:"2.5";s:13:"nb_extensions";s:2:"49";}i:2;a:3:{s:2:"id";s:2:"72";s:4:"name";s:3:"2.4";s:13:"nb_extensions";s:2:"59";}i:3;a:3:{s:2:"id";s:2:"74";s:4:"name";s:5:"2.3.5";s:13:"nb_extensions";s:2:"18";}i:4;a:3:{s:2:"id";s:2:"73";s:4:"name";s:5:"2.3.4";s:13:"nb_extensions";s:2:"19";}i:5;a:3:{s:2:"id";s:2:"71";s:4:"name";s:5:"2.3.3";s:13:"nb_extensions";s:2:"22";}i:6;a:3:{s:2:"id";s:2:"70";s:4:"name";s:5:"2.3.2";s:13:"nb_extensions";s:2:"23";}i:7;a:3:{s:2:"id";s:2:"69";s:4:"name";s:5:"2.3.1";s:13:"nb_extensions";s:2:"35";}i:8;a:3:{s:2:"id";s:2:"68";s:4:"name";s:5:"2.3.0";s:13:"nb_extensions";s:2:"51";}i:9;a:3:{s:2:"id";s:2:"67";s:4:"name";s:5:"2.2.5";s:13:"nb_extensions";s:2:"39";}i:10;a:3:{s:2:"id";s:2:"66";s:4:"name";s:5:"2.2.4";s:13:"nb_extensions";s:2:"39";}i:11;a:3:{s:2:"id";s:2:"65";s:4:"name";s:5:"2.2.3";s:13:"nb_extensions";s:2:"45";}i:12;a:3:{s:2:"id";s:2:"64";s:4:"name";s:5:"2.2.2";s:13:"nb_extensions";s:2:"41";}i:13;a:3:{s:2:"id";s:2:"63";s:4:"name";s:5:"2.2.1";s:13:"nb_extensions";s:2:"54";}i:14;a:3:{s:2:"id";s:2:"62";s:4:"name";s:5:"2.2.0";s:13:"nb_extensions";s:2:"49";}i:15;a:3:{s:2:"id";s:2:"57";s:4:"name";s:5:"2.1.6";s:13:"nb_extensions";s:2:"27";}i:16;a:3:{s:2:"id";s:2:"56";s:4:"name";s:5:"2.1.5";s:13:"nb_extensions";s:2:"32";}i:17;a:3:{s:2:"id";s:2:"55";s:4:"name";s:5:"2.1.4";s:13:"nb_extensions";s:2:"31";}i:18;a:3:{s:2:"id";s:2:"54";s:4:"name";s:5:"2.1.3";s:13:"nb_extensions";s:2:"31";}i:19;a:3:{s:2:"id";s:2:"53";s:4:"name";s:5:"2.1.2";s:13:"nb_extensions";s:2:"33";}i:20;a:3:{s:2:"id";s:2:"52";s:4:"name";s:5:"2.1.1";s:13:"nb_extensions";s:2:"44";}i:21;a:3:{s:2:"id";s:2:"51";s:4:"name";s:5:"2.1.0";s:13:"nb_extensions";s:2:"43";}i:22;a:3:{s:2:"id";s:2:"50";s:4:"name";s:6:"2.0.10";s:13:"nb_extensions";s:1:"1";}i:23;a:3:{s:2:"id";s:2:"46";s:4:"name";s:5:"2.0.9";s:13:"nb_extensions";s:1:"5";}i:24;a:3:{s:2:"id";s:2:"45";s:4:"name";s:5:"2.0.8";s:13:"nb_extensions";s:2:"14";}i:25;a:3:{s:2:"id";s:2:"44";s:4:"name";s:5:"2.0.7";s:13:"nb_extensions";s:2:"15";}i:26;a:3:{s:2:"id";s:2:"43";s:4:"name";s:5:"2.0.6";s:13:"nb_extensions";s:2:"23";}i:27;a:3:{s:2:"id";s:2:"42";s:4:"name";s:5:"2.0.5";s:13:"nb_extensions";s:2:"24";}i:28;a:3:{s:2:"id";s:2:"41";s:4:"name";s:5:"2.0.4";s:13:"nb_extensions";s:2:"21";}i:29;a:3:{s:2:"id";s:2:"40";s:4:"name";s:5:"2.0.3";s:13:"nb_extensions";s:2:"22";}i:30;a:3:{s:2:"id";s:2:"39";s:4:"name";s:5:"2.0.2";s:13:"nb_extensions";s:2:"23";}i:31;a:3:{s:2:"id";s:2:"38";s:4:"name";s:5:"2.0.1";s:13:"nb_extensions";s:2:"25";}i:32;a:3:{s:2:"id";s:2:"37";s:4:"name";s:5:"2.0.0";s:13:"nb_extensions";s:2:"27";}i:33;a:3:{s:2:"id";s:2:"35";s:4:"name";s:5:"1.7.3";s:13:"nb_extensions";s:1:"4";}i:34;a:3:{s:2:"id";s:2:"30";s:4:"name";s:5:"1.7.2";s:13:"nb_extensions";s:1:"8";}i:35;a:3:{s:2:"id";s:2:"29";s:4:"name";s:5:"1.7.1";s:13:"nb_extensions";s:2:"16";}i:36;a:3:{s:2:"id";s:2:"28";s:4:"name";s:5:"1.7.0";s:13:"nb_extensions";s:2:"22";}i:37;a:3:{s:2:"id";s:2:"26";s:4:"name";s:5:"1.6.2";s:13:"nb_extensions";s:2:"14";}i:38;a:3:{s:2:"id";s:2:"25";s:4:"name";s:5:"1.6.1";s:13:"nb_extensions";s:2:"12";}i:39;a:3:{s:2:"id";s:2:"24";s:4:"name";s:5:"1.6.0";s:13:"nb_extensions";s:1:"9";}i:40;a:3:{s:2:"id";s:2:"22";s:4:"name";s:5:"1.5.2";s:13:"nb_extensions";s:1:"5";}i:41;a:3:{s:2:"id";s:2:"21";s:4:"name";s:5:"1.5.1";s:13:"nb_extensions";s:1:"5";}i:42;a:3:{s:2:"id";s:2:"20";s:4:"name";s:5:"1.5.0";s:13:"nb_extensions";s:1:"5";}i:43;a:3:{s:2:"id";s:2:"19";s:4:"name";s:5:"1.4.1";s:13:"nb_extensions";s:1:"2";}i:44;a:3:{s:2:"id";s:2:"18";s:4:"name";s:5:"1.4.0";s:13:"nb_extensions";s:1:"2";}i:45;a:3:{s:2:"id";s:2:"16";s:4:"name";s:5:"1.3.4";s:13:"nb_extensions";i:0;}i:46;a:3:{s:2:"id";s:2:"15";s:4:"name";s:5:"1.3.3";s:13:"nb_extensions";i:0;}i:47;a:3:{s:2:"id";s:2:"14";s:4:"name";s:5:"1.3.2";s:13:"nb_extensions";i:0;}i:48;a:3:{s:2:"id";s:2:"12";s:4:"name";s:5:"1.3.1";s:13:"nb_extensions";i:0;}i:49;a:3:{s:2:"id";s:2:"13";s:4:"name";s:5:"1.3.0";s:13:"nb_extensions";i:0;}}