Fixed story chapters being unresponsive if there are no comments.

marko/page/story-content/components/create-comment-modal/component.js

@@ -30,11 +30,13 @@ module.exports = class {
 
     const comments = this.input.chapter.comments || []
     const lastComment = comments[comments.length - 1]
-    let date = lastComment.fictionalDate || chapter.fictionalDate
+    if (lastComment != null) {
+      let date = lastComment.fictionalDate || this.input.chapter.fictionalDate
       if (date != null) {
         this.change("fictionalDate", {target: {value: moment(date).format("MMM D, YYYY")}})
       }
     }
+  }
 
   change(key, ev) {
     this.state.values = Object.assign({}, this.state.values, {[key]: ev.target.value})