Hi ​@khoicity,

Thanks for posting in the Lucid Community!

Just to make sure that we are on the same page, please review our Export or print a Lucid document article from the Lucidchart Help Center. Let me know if you have any questions about how downloading/exporting your document should work.

 Once you have reviewed this article, here are some specific things to check when exporting your document:

•  Try the export in a Chrome Incognito browsing session. This often improves performance by clearing your cache and cookies and disabling your extensions.

• Is the page that you are trying to export a Master Page? If so, it will be omitted from the downloaded version of your document and you will need to convert it into a page before exporting. To do this, left-click on your Master Page tab and select "Convert to Page". 

If none of these tips help, would you mind sending me the following details so I can take a closer look at the issue? 

• A description of the download settings (file type, document pages, cropping, quality, etc.) that you selected for the download.

• If the document will export but does not look as you expected, please send me a screenshot of the exported filed that is experiencing the issue and a description of what about it is incorrect, or a screenshot of the issue in the exported document.

 Feel free to let me know if you have any further questions. Thanks for your help and patience!