I am not sure that this is related to the problem, but when installing the plugin I see these errors:
Warning: An unexpected error occurred. Something may be wrong with www.remarpro.com or this server’s configuration. If you continue to have problems, please try the support forums. (WordPress could not establish a secure connection to www.remarpro.com. Please contact your server administrator.) in C:\xampp\htdocs\Wordpress_Client\wp-includes\update.php on line 155
Warning: An unexpected error occurred. Something may be wrong with www.remarpro.com or this server’s configuration. If you continue to have problems, please try the support forums. (WordPress could not establish a secure connection to www.remarpro.com. Please contact your server administrator.) in C:\xampp\htdocs\Wordpress_Client\wp-includes\update.php on line 347
Warning: An unexpected error occurred. Something may be wrong with www.remarpro.com or this server’s configuration. If you continue to have problems, please try the support forums. (WordPress could not establish a secure connection to www.remarpro.com. Please contact your server administrator.) in C:\xampp\htdocs\Wordpress_Client\wp-includes\update.php on line 525
And then when you activate it:
The plugin generated 408 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin.