Views show fields is set, but only "Content" options are available to select - why?
The Content: Body field should be there as long as it exists in the content type.  

A couple things you can try in this order:


Ensure all permissions are set properly
Flush all caches
Flush the views cache at /admin/structure/views/settings/advanced
Disable views cache just to see if that's an issue
Update Views


Here's a current issue of the problem