Hello,
Thank you for contacting Rank Math and bringing your concern to our attention. I’m sorry for any inconvenience this issue may have caused you.
1. From the error message, it seems that the mbstring is disabled on your site. Could you please confirm if you have enabled the PHP module mbstring on your server?
If you are not sure about this, please get in touch with your hosting provider as they will be able to clarify that.
We ask that, because that is a required module to use our plugin completely, and if it’s not enabled functions such as this one will fail to load.
2. You can whitelist our IP 134.90.148.114 and the user-agent RankMathAPI/2.0.0; https://rankmath.com
.
Let us know how this goes.
Thank you.
That worked! Thank you for your help! 🙂
Hello,
We are super happy that this resolved your issue. If you have any other questions in the future, know that we are here to help you.
If you don’t mind me asking, could you please leave us a review (if you haven’t already) on https://wordpress.org/support/plugin/seo-by-rank-math/reviews/#new-post about your overall experience with Rank Math? We appreciate your time and patience.
If you do have another question in the future, please feel free to create a new forum topic, and it will be our pleasure to assist you again.
Thank you.