Post revisions don't save or show up for all custom post types

Question

My website makes use of a number of custom post types as well as the traditional "posts" and "pages" types. For all "posts" and "pages" revisions show up as they should, with a history of edits visible, the option to compare posts, and so on. For all custom post types, I have no revision history at all. I've enabled revisions when defining each of these post types in functions.php, so on each of these post types I get a blank tab that says "Revisions" but does not display or collect any revisions data.

I'm at a loss for how to fix this and any help would be appreciated!

Thanks in advance for any assistance.

I could post my functions.php file if it helps solve this... just ask.

Answer 1

I know this is an old Q, but just had the same problem and fixed it...

In your custom post type args array (in functions.php) add 'revisions' to the 'supports' array:

$args = array(....., 'supports' => array(..., 'revisions'),......);

Note however that this wont take effect for old pages of this post type, just new ones created from now on

If you're doing anything to do with custom post types, this article is awesome.