Thanks for the advice, Bob, but this made absolutely no change.
Photoshop CS6 was created quite a bit before Mac OSX Sierra became available.
I would recommend taking a look at the following link & trying the referenced plug-in.
Hi, Jasper. What you suggested seemed to be the answer to this problem. However, I downloaded and installed the plug-in, logged out and in again, started Photoshop, and there was absolutely no difference. Sorry! Thanks for your interest, though.