How to remove Spire.XLS signature from pdf File?

I'm working on java, i have an excel file named "file.xlsx" that i want to convert to pdf using Spire.XLS , this is the code i wrote for that :

            //Create a Workbook instance
            workbook = new Workbook();
            //Load an Excel file
            workbook.loadFromFile("file.xlsx");

            //Get the first worksheet
            sheet = workbook.getWorksheets().get(0);
            //Add a new worksheet to the workbook
            sheet_copy = workbook.getWorksheets().add("Copy of sheet1");
            //Copy the first worksheet to the new worksheet
            sheet_copy.copyFrom(sheet);

            //Save the result file
            workbook.saveToFile("file.xlsx");
            
            workbook.saveToFile("result.pdf", com.spire.xls.FileFormat.PDF);

The pdf file is generated but with a signature : Evaluation Warning : The document was created with Spire.XLS for Java , i'm wondering about how to remove it , any idea ?

Solution

Either Request a pro Trial License OR

Per the age old answer use the free version

Free version doesn't have evaluation warning on result file. Please make sure the version you were using is correct,

https://www.e-iceblue.com/forum/evaluation-warning-the-document-was-created-with-spire-pdf-t4925.html

https://www.e-iceblue.com/Download/xls-for-java-free.html

or for .net users

https://www.e-iceblue.com/Download/download-excel-for-net-free.html