After an initial test, I observed the issue as you mentioned by opening and re-saving the template XLSM file, the output file is corrupted when opening it into MS Excel.
e.g
Sample code:
Workbook wb = new Workbook(“template.xlsm”);
wb.save(“out1.xlsm”, SaveFormat.XLSM);
I have logged a ticket with an id “CELLSJAVA-41097” for your issue. We will look into it soon.
Once we have any update on it, we will let you know here.
Thank you for the confirmation. We may now close the aforesaid ticket, Please feel free to contact us back in case you need our further assistance with Aspose APIs.