Hi,
I and my team are facing an issue when we are trying to convert an xls file to PDF.
Scenario: These specific xls files are system generated meaning - they were downloaded from another web application and are being uploaded to my application and we need to convert that file to PDF. We are unable to convert these files to PDF.
Please note that when we open this xls file on the desktop, you get a warning "File format and extension of 'sample.xls' don't match. The file could be corrupted or unsafe. Unless you trust its source, don't open it. Do you want to open it anyway?". On clicking yes, we can open the file.
In the Spire.XLS ddl, we are getting exceptions at FileLoad.
On extensive research we found the problem, It is called Extension Hardening.
Does anyone know how to fix this problem? I am attaching a sample file for your reference.