Menu items corrupt

I am having a problem with my site https://www.muskat.co.za/realestate

The site was working and I made some changes by changing the post to draft and I made some changes to the existing pages. Now I can only access the menu item on the fisrt page, none of the other pages load either from the menu or the slides, please help as I need to sort this out urgently.

I have upgraded wordress to the latest version and the problem stil persisit