Thanks for the replies. After seeing that other people had no problems, I went back and tried a bunch of things, from uninstalling and reinstalling LR, (ended up with the 2015 version!) to uninstalling all of it, from the Creative Cloud through Photoshop. The behavior is quite bizarre. Episodically it will work, then a few minutes later, it's back to the plus sign and no TAT.
There must be something wrong in the depths of my laptop. Still afraid to do my Mac Pro desktop but it's not really critical to my work so I'll wait for a while.
Only jedbest seems to have had a similar experience. I'd love to hear more from him. Not sure how to proceed since I've uninstalled and reinstalled multiple times to no avail, even had a failure to install event. If all else fails I'll call Adobe but have not had wonderful experiences in the past when doing that.
Eric