Clicking the "I accept" button opens the 20-page report, which is NOT visible until they agree.
Clicking the "I do NOT accept" button closes the file.
Here is what I have done:
Opened the 2-page PDF legal agreement in Acrobat.
Attached the PDF of the 20-page report as an Attachment.
Added the buttons to the bottom of the 2-page confidentiality agreement using the "Rich Media => Add Button".
Linked the "I accept" button to the attachment
Linked the "I do not accept" button to the menu item File>Exit.
Set a security password to prevent printing and editing and then Saved the file
THE PROBLEM: If someone opens it in Acrobat, all they have to do is open the Attachments pane and they can see the report without having to accept the confidentiality agreement.
How do I protect this report so nobody can open it unless they accept the 2-page confidentiality agreement?
Even if you were able to create the user experience you want in Acrobat, you can't guarantee that experience transfers to other PDF viewers including Adobe Acrobat Reader on mobile. Unless you can't have secure attachments in an unsecured file and expect them to not be accessible to anyone. I'm also quite sure you saw something that looked like what you are asking for; I doubt it was secure either. If you want a secure system I strongly recommend you invest in a DRM solution.