Insert PDF is greyed out on my container field

The Insert PDF context menu item is greyed out on my container field when I have my database open locally. My Google Fu has failed me on solving this.

• My container field is on a layout, not in a portal.
• I have Interactive Content checked.
• I have a PDF viewer working in IE. (Zeon - I do not know where I got this plugin - I very rarely use IE.). I also have an older version of NitroPDF Pro which I use daily, but no IE plugin at the moment.
• The container field Storage settings are "Store container data externally" and using Open storage option. I also tried the secure storage option which was the default.
• I have FM Pro 14.0.4 and this database is not converted from earlier version.
• I am using Windows 10
• I can drag and drop a PDF into the container and I get the PDF icon, but it is not interactive
• However it is interactive (both native and WebDirect) when I upload the database to FM Server - which is also my local computer for now. 
• But in all cases Insert PDF is greyed out.

The only other solution that the web has coughed up it to use the newest version of Adobe Acrobat Reader which is not an option - I refuse to use that piece of #$@&.

What else can I try?

Thanks, Brad