Page Layout: This Control is Currently Disabled

Issue:

Page Layout: This Control is Currently Disabled.

Work around:

Make sure the page is checked out and editable

Click on the Save & Close Drop down arrow button

Click Save and Keep Editing

This will refresh the page and now you should be able to click on the page layout drop down.

Reference:
http://erikswenson.blogspot.com/2011/05/page-layout-this-control-is-currently.html