Pokémon Go takes the modern path to success. They enabled their users. What is it that has led it to become the most downloaded game in the app store with over 5% of worldwide users on android installing it in the first 2 weeks? The marketing model. When we look at competing games in the app…
Awesome! This page is mobile friendly!
So with Google making plans to favor sites that are designed to render correctly on all devices they have made a page to check where you stand here (https://www.google.com/webmasters/tools/mobile-friendly/), where you can check your page with google for mobile devices.
On checking a site of mine today It gave 29 errors and deemed the site not mobile friendly. This is odd since it looks great on all devices when I view it with any browser, but an obvious issue.
This means when Google and I view it something must differ. Google provides a sample screenshot of what “they saw” and it showed my menus a mess in mobile. This means it is the css file not being seen being accessed by Google.
This site had a dated Robots.txt file that was blocking things that should no longer be blocked like CSS JS and the plugins directory. Plugins may call their own CSS files which would in turn render you page wrong and cause mobile failing grades as viewed by Google.
This topic was first covered by Yoast here where he references this live blog confirming the issue with using an out of date robots.txt file for WordPress sites.