Member Directory has an error

I tried to add your “GD Member Directory” but when I try to open the Settings, I have this message:

Fatal error: Uncaught Error: Class 'Dev4Press\v37\Plugin\GDMED\Admin\Panel' not found in E:\vhosts\forum.puresourcecode.com\httpdocs\bnetwork\wp-content\plugins\gd-members-directory-for-bbpress\core\admin\panel\Install.php:11 Stack trace: #0 E:\vhosts\forum.puresourcecode.com\httpdocs\bnetwork\wp-content\plugins\gd-members-directory-for-bbpress\core\autoload.php(25): include() #1 [internal function]: d4p_plugin_gdmed_autoload() #2 E:\vhosts\forum.puresourcecode.com\httpdocs\bnetwork\wp-content\plugins\gd-forum-manager-for-bbpress\d4plib\dev4press\core\admin\Plugin.php(385): spl_autoload_call() #3 E:\vhosts\forum.puresourcecode.com\httpdocs\bnetwork\wp-content\plugins\gd-forum-manager-for-bbpress\d4plib\dev4press\core\admin\submenu\Plugin.php(72): Dev4Press\v37\Core\Admin\Plugin->screen_setup() #4 E:\vhosts\forum.puresourcecode.com\httpdocs\bnetwork\wp-includes\class-wp-hook.php(307): Dev4Press\v37\Core\Admin\Submenu\Plugin->current_screen() #5 E:\vhosts\forum.puresourcecode.com\httpdocs\bnetwork\wp-includes\class-wp-hook. in E:\vhosts\forum.puresourcecode.com\httpdocs\bnetwork\wp-content\plugins\gd-members-directory-for-bbpress\core\admin\panel\Install.php on line 11