WordPress errors on plugin activation

Hi there, I have a problem with a wordpress plugin I made. When I tested it on localhost it worked just fine, but when I try to install it on my website I have the following errors:

Warning: include(include/helpers/wg_Common_Helper.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 21

Warning: include(include/helpers/wg_Common_Helper.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 21

Warning: include(): Failed opening 'include/helpers/wg_Common_Helper.class.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 21

Warning: include(include/helpers/wg_Settings_Helper.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 22

Warning: include(include/helpers/wg_Settings_Helper.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 22

Warning: include(): Failed opening 'include/helpers/wg_Settings_Helper.class.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 22

Warning: include(include/helpers/wg_Product_Helper.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 23

Warning: include(include/helpers/wg_Product_Helper.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 23

Warning: include(): Failed opening 'include/helpers/wg_Product_Helper.class.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 23

Warning: include(include/helpers/wg_Criteria_Helper.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 24

Warning: include(include/helpers/wg_Criteria_Helper.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 24

Warning: include(): Failed opening 'include/helpers/wg_Criteria_Helper.class.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 24

Warning: include(include/admin/wg_Admin.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 25

Warning: include(include/admin/wg_Admin.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 25

Warning: include(): Failed opening 'include/admin/wg_Admin.class.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 25

Warning: include(include/admin/wg_Single_Gift.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 26

Warning: include(include/admin/wg_Single_Gift.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 26

Warning: include(): Failed opening 'include/admin/wg_Single_Gift.class.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 26

Warning: include(include/wg_Frontend.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 27

Warning: include(include/wg_Frontend.class.php): failed to open stream: No such file or directory in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 27

Warning: include(): Failed opening 'include/wg_Frontend.class.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/woocommerce-gifts.php on line 27

Fatal error: Class 'wg_Common_Helper' not found in /home/whowpcom/public_html/view/wp-content/plugins/woocommerce-gifts/include/Woocommerce_Gifts.class.php on line 16

Please help me if you know what is causing this errors! Thank you in advance.