Cannot create new Top Level page in 2.7

I'm new to Perch and trying to create a demo site from scratch. I've watched all the vids & read a bunch already but try as I might I can't seem to create a new Top Level page from within perch and I don't know what I'm doing wrong. I can create sub pages fine but that's not what I want to do right now.

If I select "Top Level" in the Parent Page dropdown, and set Master Page to use the Default page template I always get the following error message

Fatal error: Call to a member function pageSubpageRoles() on a non-object in /Users/larry/Sites/perchtest/perch/core/apps/content/PerchContent_Pages.class.php on line 497

Can anybody tell me what I'm doing wrong?