Lead Developer
Hi there,
This typically happens when you use the Mobile Theme from Jetpack – if you’re not intentionally using the Mobile Theme, you can turn it off by going to “Jetpack > Settings”.
However, I do believe I have fixed this in a recent version of Typography/GP Premium to hide the error. What version are you using? You can check in the “Plugins” area of your Dashboard.
Let me know 🙂