JQuery, JSON, iframe, and quotation marks do not work together

Produce upload file in an iframe(a different kind of way). In response, generate a JSON object where one of the fields is a string with the html describing the error.
Question: How do I get this response from the server without breaking it?

When I use .text() from JQuery all tags are removed.
When I use .html() from JQuery it "corrects" the html and then it is not possible to do the deserialization of the JSON because the quotes are losing the escape character. we get Invalid JSON.