Why do I recieve this message when I go to the register.php?

I didnt even touch that file... why is it saying this?

Warning: main(XOOPS_ROOT_PATH/class/xoopsblock.php): failed to open stream: No such file or directory in /home/itzarap/public_html/header.php on line 28

Warning: main(): Failed opening 'XOOPS_ROOT_PATH/class/xoopsblock.php' for inclusion (include_path='.:/usr/local/lib/php:/usr/lib/php') in /home/itzarap/public_html/header.php on line 28

Warning: main(XOOPS_ROOT_PATH/class/template.php): failed to open stream: No such file or directory in /home/itzarap/public_html/header.php on line 62

Fatal error: main(): Failed opening required 'XOOPS_ROOT_PATH/class/template.php' (include_path='.:/usr/local/lib/php:/usr/lib/php') in /home/itzarap/public_html/header.php on line 62