Hello,linhkburh
Thanks for your feedback! I noticed that the version you are using is not our latest free version(
Free Spire.XLS for Java Version:5.3.0). You can update it before testing. In addition, we do not regularly update and maintain the free version, and the free version has some limitations, when converting Excel files to PDF files, you can only get the first 3 pages of PDF file.
We recommend you use our latest commercial version(
Spire.XLS for Java Version:14.10.0) for testing. We are willing to provide a temporary license (one month free) to help you remove the warning message and evaluate our commercial version better. If you need it, please provide us with feedback.
Sincerely,
Amin
E-iceblue support team