Ajax error while saving a view When I edit a view, and click on the "Save" button, I get the following message:


  An AJAX HTTP error occurred.
  HTTP Result Code: 200
  Debugging information follows.
  Path: /admin/structure/views/view/vouchers_list/preview/page/ajax
  StatusText: OK


What does that message mean? How can I fix the error?
When you make a change to a view in the UI and click "save" before the preview has finished loading, you'll get this error. It's simply because you've made a 2nd request to the server while the ajax request to load the preview is still running. 

You can either wait for the preview "loading" icon to finish before you save the view, or you can ignore it :)