3.7.2 update App Store error (20) and manual download error.

I purchased 3.7 from App Store. App Store prompts to update to 3.7.2 but when I start the update I get errror "We could not complete your request. There was an error in the App Store. Please try again later. (20)"

I've tried several times over the past week with the same result.

Today I manually downloaded the admin update. But when I try to run it I get error "The version of Remote Desktop installed on this Mac must be updated through the Mac App Store."

Grrr. How can I resolve this?

Mavericks 10.9.2