Need Woocommerce/Wordpress Update Issue Fixed

I run a clients woocommerce store, I recently tried the to add the courier guy plugin on the site and as soon as adding it the website showed a critical error page. I then deactived it but it still showed the same error. In the process I also updated woocommerce to the latest version. I then deactivated all the plugins and reactivated then one at a time and realized a NotificationX plugin caused the site to not show. After activating everything except NotificationX the website came online. Now the site is working however there is issues in the backend. If I try to change menu items, if I click on the drop downs it does not slide down as normal. It refreshes the page with each action that I do. Also if I try to edit products I am unable to click on variations, attributes or the other options, it simply does nothing. Can someone who knows this error help me. No chancers!!