The FileOpen plugin is a small extension (or "add-on") for Adobe Acrobat and Adobe Reader. While Adobe’s native software has its own security features (like simple passwords), many corporations, legal firms, and academic publishers require a higher level of control.
This usually means there is a conflict between the version of the plugin and your Adobe Reader.
Publishers can restrict printing, prevent screen captures, and set expiration dates even after a document has been downloaded.

