to see revisions, you might need to tick the ‘revisions’ tick-box after clicking the ‘screen options’ tab on the ‘edit post’ page.
Nope, there is no option there.
the ‘screen options’ tab is near the top right on the dashboard – all posts – edit post page
http://codex.wordpress.org/Posts_Add_New_Screen
Yes, I knew where you were referring to, but there is no check box in that place. I visited the page you linked to, and see that it used to be there, but in 4.0 it doesn’t appear to be there (or at least not in my version).
the screen option for revisions is still there in wp4.0 and wp4.0.1.
did you possibly remove revisions with an entry in wp-config.php?
http://codex.wordpress.org/Revisions
does anything change when you temporarily switch to the default theme Twenty Fourteen, and when you deactivate all plugins?
Ok, I did another test and uncovered what was happening. I edited the “Hello World” post that comes with a fresh install. After one edit there was no revision history (and thus not in the screen options drop down). I did another edit of the post and finally the revision history appeared (and appeared in the screen options drop down).
When there is just one revision there is no history, but once you get the 2nd revision it appears.
Thank you for your help.