Situation: When opening or saving a PDF file, you cannot change security on this document because the document is signed or certificate. you may receive this message: You cannot change security on this document because the document is signed or certificate.
Resolution 1: If you receive this PDF form someone, you may need to upgrade Adobe Acrobat to a new version.
Resolution 2: You may try to print the file to PDF using Adobe PDF or Microsoft Print to PDF.
