Thanks Abhishek, the font is installed on my machine. It's an Architectural Font that I purchased and own. My Design App has successfully published to PDF files for over ten years with no issues. I haven't updated my Design App (ArchiCAD) in over a year. Adobe Reader likes to update weekly it seems. Just recently this malfunction has occurred. Now Adobe allows me to publish files with default fonts such as Arial but not with my Fonts that I own and use.
thomas