BigSur upgrade breaks the share menu option in Safari

I've just upgraded to Mac OS X Big Sur (Version 11.01) from Catalina. Normally in the browser or finder you can select the 'Share' to send information to another application. For example, if browsing a site and want to save the information I would typically select the 'Share to' icon, select Notes and then my information would be saved. After upgrading to Big Sur I've hit the following issues: 1. Share menu in Safari is empty 2. Selecting the 'More' option pops up the Extensions preference which is all blank Now if I try the path of going to the Safari option to add an extension the new functionality in BigSur pops open the App Store. I can select an option and after installing it then says to return to the Extensions 'management' screen but nothing is able to be selected or activated. Net result - stuck ! Does anyone have any suggestions