Today when I tried to enable page-level ads of google adsense, I met below error:
This page cannot display anchor ads for the following reason(s):
- The viewport is not between 320 and 420 pixels wide.
- The current browser is not supported.
The cause by this is that the wordpress theme currently used didn't support viewport(more info about viewport is here). To enable viewport, we can install one plugin - Definitely allow mobile zooming. After activating them, you can try again.