Poke it.
I notice that sometimes giving the program a poke helps. In effect you want to "get to" or "poke" the recalcitrant tool
by affecting an unrelated feature that "calls" or somehow forces the tool to respond. Terrible explanation, so here's an example:
I usually create a shortcut for a "poke". Open the Work Environment, go to Shortcuts, scroll down the list of menus to Design, then click on SEO's and create your keyboard short cut.
If you can even do this, maybe we have ignition. Assuming success, use your shortcut to invoke SEO's. Now, is the menu item still greyed out?
This is one of my "when all else fails" techniques. I still think a reload is your friend.
Snap