autocorrect stopped entirely ( on Windows 7)

Autocorrect Options Replace was working earlier today. Without any symptom I noticed, it no longer replaces text, at all. Rebooted. Didn’t help. Didn’t change anything that I’m aware of. I can still see them in the Autocorrect Options Replace window. They just don’t respond. I depend on them extensively and simply cannot function without them.

??? For no reason, again, they now work. Befuddling but (I guess) solved.