I am having the exact same problems with customisation. All that is listed is Widgets, and that only leads on to a help text mentioning to set navigation. My site is being recreated on a new server http:/18.104.22.168/cheeserightandmorte.co.uk/wordpress/ and I installed the latest version of WordPress and downloaded the latest theme from your site. Customise is the only option that is not working correctly. I have loaded in the themes supplied with WordPress and these all work correctly. Any suggestions?