该问题是与机器人工作室的索引。

The problem was with android studio indexing.

按照以下步骤。

进入文件>无效缓存/重启

Go to 'File' > 'Invalidate caches/restart'

现在的工作室将关闭并重新启动。现在索引开始。在索引完成后，你会发现意见箱与每一个可能的建议。

Now the studio will shut down and restart. Now indexing begins. On completion of indexing you will find the Suggestion boxes with every possible suggestions.