fix

public/react/src/modules/courses/common/comments/commonent-item/index.jsx

@@ -157,8 +157,7 @@ export default ({ confirm, item, showNotification, replySuccess, isStudent, isAd
   const isAppealing = homework_status && homework_status.indexOf('申诉中') != -1
 
   const md = useMemo(() => {
-    let rs = markdownToHTML(content)
+    return content ? markdownToHTML(content) : ''
-    return rs
   }, [content, id])
 
   return (