It’s very likely that there’s some problem when the server were you installed the product tries to connect to Instagram server via SSL, so:
– what version of PHP is you server running?
– is the CURL extension installed with SSL support enabled (CURL is used for the connection, using a mandatory secure SSL connection)?
– are you testing the plugin on a local or remote server?
Can you read the php log file and see if there’s any error?
In case PHP is at least 5.2 and CURL is installed, there’s probably some error regarding SSL connection. In this case, you can try decommenting this line:
//curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
to
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
in instagram/instagram.php file inside the plugin directory (it tells the server not to check for valid server,, in case you server doesn’t have an updated list of valid servers).