import * as React from "react";
import { SurveyQuestionElementBase } from "./reactquestionelement";
import { QuestionHtmlModel } from "../question_html";
import { ReactQuestionFactory } from "./reactquestionfactory";

export class SurveyQuestionHtml extends SurveyQuestionElementBase {
  constructor(props: any) {
    super(props);
  }
  protected get question(): QuestionHtmlModel {
    return this.questionBase as QuestionHtmlModel;
  }
  render(): JSX.Element {
    if (!this.question || !this.question.html) return null;
    var htmlValue = { __html: this.question.locHtml.renderedHtml };
    return (
      <div
        className={this.question.cssClasses.root}
        dangerouslySetInnerHTML={htmlValue}
      />
    );
  }
}

ReactQuestionFactory.Instance.registerQuestion("html", props => {
  return React.createElement(SurveyQuestionHtml, props);
});

import * as React from "react";
import { SurveyQuestionElementBase } from "./reactquestionelement";
import { QuestionHtmlModel } from "../question_html";
import { ReactQuestionFactory } from "./reactquestionfactory";

export class SurveyQuestionHtml extends SurveyQuestionElementBase {
  constructor(props: any) {
    super(props);
  }
  protected get question(): QuestionHtmlModel {
    return this.questionBase as QuestionHtmlModel;
  }
  render(): JSX.Element {
    if (!this.question || !this.question.html) return null;
    var htmlValue = { __html: this.question.locHtml.renderedHtml };
    return (
      <div
        className={this.question.cssClasses}
        dangerouslySetInnerHTML={htmlValue}
      />
    );
  }
}

ReactQuestionFactory.Instance.registerQuestion("html", props => {
  return React.createElement(SurveyQuestionHtml, props);
});

--- 
+++ 
@@ -15,7 +15,7 @@
     var htmlValue = { __html: this.question.locHtml.renderedHtml };
     return (
       <div
-        className={this.question.cssClasses}
+        className={this.question.cssClasses.root}
         dangerouslySetInnerHTML={htmlValue}
       />
     );
Fix the bug with html question css class in react
