A number of member are reporting problems being able to edit module or articles after upgrading Joomla to 3.6.3 or higher. You must clear your browser cache after updating (clear server cache too). Previous versions of Joomla Javascript (cached in your browser) will not work with you updated version of Joomla in the backend.
Please search forums before posting. Please make sure your post includes the version of the CMS you are using and a link to the problem. Annotations on screenshots can also be helpful to explain problems/goals. Please use the "secure" tab for confidential information.