There should be no content in the directory. If there is any content in your thesis directory, it is likely that you made a mistake when editing the thesis directory and accidentally edited the content into the directory. At this time, you should correct it as soon as possible, because it is absolutely not allowed.

Hold down Ctrl and click on this part of the directory, and you will find this part in the text. Select a non-directory and set the style to text, or use the format brush to brush this section in the same format as other text.