Menu items issue – menu save failing

Hi, I hope you can help. Since 4.2.2 update I’m unable to add all the required pages to the menu. When it saves it comes up with a fail message. If you go back pages on the menu are missing. If you refresh the same problem. All help appreciated. I haven’t edited any css, just using the regular theme pages. One error is The given object ID is not that of a menu item.