Hi,

We checked and figured out the the error comes from your module YoastSeo (js error). This makes our MD awecontent uneditable. 

YoastSEO_DrupalSource.prototype.getDataFromInput = function( field ) {
return document.getElementById(this.config.fields[field]).value;
}

We received your email in the late yesterday afternoon with report of back-end error and I did reply you already. 

You told me that the issue remained over a week without any solution provided. However, I checked, both in support forum and email, and saw no report from you about this error. Thus, we suggest you to post in our support forum (make a new thread like this post) if you have any issue or question. That would be much better for both of us to follow up the problem