Drupal Display "Master" Error in View While I'm creating view displays for three of my content types, created first two and auto previews look fine. When I created the third one, the server kinda went down for a while. So I waited till it comes back online, I'm no longer able to auto preview any of the displays, and I'm getting the following error


Display "Master" uses fields but there are none defined for it or all
are excluded. 
Display "Page" uses fields but there are none defined
for it or all are excluded.


Help will be appreciated. Thanks
Check to make sure you have at least one field listed under 'Fields.'  If you use a display type that requires fields without any being selected you will see the error noted in your question.

If it's bugging out, try to cancel your changes and refresh the page.  Add a field, save and see if the preview works again.