error message

First, thank you for creating and maintaining such a powerful plugin. It’s worked flawless for many months.

Now recently, I’m getting this message in dashboard:

You are using W3 Total Cache but W3 Total Cache support is not enabled…

But when I go to plugin settings and enable W3TC support, all ad locations on pages show a shortcode (not an ad).

Is there another step I need to take?

Thanks for any suggestions.