paper generating re-construction

src/views/questioncenter/generating.vue

@@ -90,7 +90,8 @@ export default {
   },
   watch: {
     currentTab: function(newVal) {
-      const key = newVal.content
+      const key = newVal?.content
+      if (!key) return // safe check
       if (this.tabVisited.includes(key)) return
       this.tabVisited.push(key)
     }