Can someone show me how to get stop this security pop up?

[Andre P.]

Every time I open a pdf file a pop up window appears " I click "yes" and it pops up again. I have go throu gh the process 4 times before it goes away, driving me crazy. Thanks.

[Thom Parker]

The problem is with the security or a feature on the PDF. Talk to the person who created or provided the PDF. 

[Andre P.]

Hi Thom, thanks for the quick, however, the problem persists with all PDFs and I receive them from mutiple sources so O suspect the proble is at the receiving end. This only started a few weeks ago. Never had this issue prior.

[Thom Parker]

Ok, that's bizarre.  It seems then that a change may have been made to your Acrobat Install. The message would indicate that Acrobat is trying to connect to an https server with an invalid certificate. It's possible that this message is erroneous, or maybe there is somekind of malicious software at work.

Have you installed anything new into Acrobat? or performed any other activitly that conincided with this behavior?

I would suggest trying to repair Acrobat first. If this doesn't help. Do a clean re-install, which means deleting any add-ins and settings, as well as un-installing Acrobat. 

Here's a link to the official Adobe Acrobat Cleaner

https://labs.adobe.com/downloads/acrobatcleaner.html

[ls_rbls]

++ Adding to this discussion,

You need to click on "View Certificate" and "More Info" to see what is the real reason for this popup.

From what it looks like, it is possible that these PDFs try to connect to website because they have a root certificate that is not trusted yest; you have to install it.  Otherwise this warning will continue to pop until you install these root certificates and manually trust them.

If you don't see the certificate information provided by the popup you cannot confirm if it is malicious or not as pointed out by ACP Thom Parker.

See this Adobe Helpx guidance: Install the GlobalSign Root CA certificate 

In addition, go to EDIT--->>> PREFERENCES --->>> TRUST MANAGER and check the following settings as outlined in the slide below:

[ls_rbls]

More on this topic is explained in great detail in the following document:

Acrobat Digital Signature User Guide 

See Page 31, "Managing Certificate Trus and Trusted Entitites"