Access Post Group settings appearing blank on single post edit screen

Symptoms

Toolset Access offers Post Groups to be set on single Posts edit screens. This is done by clicking Change Post Group in the Post Group box when editing a post.

Since Access 2.7, the pop-up dialog that appears when clicking Change Post Group is blank.

Workaround

You can edit the Post Group on the Toolset -> Access -> Post Groups and add single posts using this editing interface, or, you can add to the user the Access Capabilities (access_change_post_group, access_create_new_group) and if not already added, the manage_options capability, to resolve this issue temporarily.