Along with Adobe Acrobat Reader and Acrobat Pro, Vitrium's protected PDF files also work with PDF-XChange. This PDF viewer is only available for Windows users.
A free download is available here: https://www.tracker-software.com/product/pdf-xchange-viewer
Steps to follow BEFORE opening a Vitrium protected PDF file:
- Open PDF-XChange
- Ensure "Enable global object security policy" is UNCHECKED (disabled)