I cannot get Preview to work when editing a post. I've gotten 3 forms of an error. 1. Uh oh message (can't find post) 2. 404 message 3. You don't have permission to view posts. The messages are not exact but you get the picture. If I am the only one then maybe it is a plugin I have active. Let me know if others have same problem.
Note - this has worked for months with previous versions.
One other oddity... the version at the top of this form does not provide 2.7 as a option.