plugin repository could not be contacted (Dokuwiki)

I am using Dokuwiki on my pc but suddenly getting this error. Now, i can't see the installed plugins and templates in Extension Manager(Admin). Just getting this error The plugin repository could not be contacted. Make sure your server is allowed to contact www.dokuwiki.org and check your proxy settings. [Retry]

I Installed it using xampp and dokuwiki(from youtube video)

I am using Windows 7 (64 bit).

Please help me regarding these problems, Thanks

Regarding invisible installed plugins. I'm occasionally experiencing the similar issue but had no time to investigate. Try the following steps:

• Open Admin -> Extension manager.
• Uncheck 'updatable' checkbox.
• Switch to 'Installed templates' tab.
• Switch back to 'Installed plugins' tab.

If did not help try to play with the state of other checkboxes and switching to another tab and back. Please share your findings afterwards.

Regarding the error message check this question.

• If it worked before and now you are experiencing sudden problems then check what was changed in your computer or network settings.
• Check proxy settings in Admin -> Configuration Settings -> DokuWiki\Network.
• Check if you can access http://www.dokuwiki.org/lib/plugins/pluginrepo/api.php?cmd=ping in your browser to decide whether you need to continue investigation on network or xampp side.
• You can always install plugins manually, you aren't going to do it every day.