I just upgraded to CiviCRM 4.7.16 (Wordpress 4.7.2) and my WYSIWYG editor has disappeared from the CiviMail editor. The HTML email only allows me to enter raw HTML.
Any idea what happened and how I can restore the WYSIWYG editor?
Well, it works again through magic and voodoo. All I did was go to the Wordpress Access Control page as Christia recommended and clicked "Save". I didn't modify any settings. Just clicking "Save" seems to have reconnected everything.
What WYSIWYG editor are you using? IF CKEditor, reestablish roles and permissions for the CKEditor by going into the configuration settings for text editors on your CMS side and make sure it's still set as the default editor. This is what I had to do after updating to 4.7.15.
Here is a screenshot on Drupal to give you an idea of what I mean. If someone can post/edit this post with the WP version, that would be great.
Also, you could check the Wordpress user roles and permission from CiviCRM under Administer > Users and Permissions > Permissions (Access Control). It might be different in WordPress, but I would check that first.
I know Wordpress is really different so I'm not sure how helpful this would be for you but the bottom line is to find the settings for making sure it's still default and can still be used by the intended users.