Error:  Data structure returned is not convertible in the requested format. Try to call this method with the parameters '&format=original&serialize=1'; you will get the original php data structure serialized. The data structure looks like this: 
 $data = array (
  'info' => 
  array (
    'description' => 'Counter_PluginDescription',
    'homepage' => 'http://xn--80aeqbhthr9b.com/en/others/piwik/10-piwik-graphical-counter.html',
    'authors' => 
    array (
      0 => 
      array (
        'name' => 'Viper',
        'homepage' => 'http://киноархив.com/',
      ),
    ),
    'license' => 'GPL v3+',
    'version' => '3.0.2',
    'theme' => false,
    'require' => 
    array (
      'piwik' => '>=4.0.0-b1,<5.0.0-b1',
      'php' => '>=7.2.5',
    ),
    'name' => 'Counter',
    'license_homepage' => 'http://www.gnu.org/licenses/gpl-3.0.html',
    'keywords' => 
    array (
      0 => 'piwik',
      1 => 'counter image',
      2 => 'image counter',
      3 => 'piwik visible counter',
      4 => 'show hits piwik',
      5 => 'show visits piwik',
    ),
  ),
  'activated' => true,
  'alwaysActivated' => false,
  'missingRequirements' => '',
  'uninstallable' => true,
);