This is a security level recently introduced by Safari, beyond our control. You can try one of the following options:

– install Google Chrome if it is not already installed on your computer, tablet or smartphone,

– install Acrobat Reader, which opens these documents

– click on the message that appears: “Module blocked”. When the approval dialog box appears, select “Trust” (here’s the Adobe explanatory page: https://helpx.adobe.com/fr/acrobat/kb/blocked-plugin-alert-safari-7.html).