The exported DXF is missing.
In case you find out that your DXF generation does not work properly, please kindly check your file's name in prior. If it is too long, or contains special characters such as symbols or non-English alphabets, it may affect generation errors. In addition, please confirm the name of saving folder and the path to the foler. If they contain special characters, it may also cause errors.
The best way will be to save the subject file on your desktop with a short and simple name.