This happened today out of nowhere
Fatal error: Class 'ZipArchive' not found in /home/hardcore/public_html/ow_system_plugins/admin/controllers/plugins.php on line 204
please help an why did this happen, was installin a new pluigin
That means that someone accessed your site either hiding their browser or will not allow the webserver to detect the browser in some way.
That is not an error that is a notice, notices are not fatal and most of the time you can just ignore them. There are some notices that require correction to the site but in this case just ignore it and remove those from your log.
There is some htaccess code i believe that you can use to handle such absence of data but im not a htaccess guru so i dont know what that is.