The most recent versions of Adobe Reader install a new security feature. When in place, any attempt to open a PDF file within Safari is initially blocked. In order to get the PDF to open, you have to negotiate two warning messages.
Call me reckless, but I am not especially concerned about the security risk here. I would much rather avoid the hassle of having to deal with the warnings each and every time I attempt to load a PDF. So, I set about to disable the feature. Figuring out how to do so turned out to be more work than I had anticipated.
My first stop was the Preferences settings in the Adobe Reader application. I checked the “Security” and “Security (Enhanced)” settings. Nope. Nothing to see here. Next, I checked out the promising-sounding Trust Manager. Close, but no cigar. This controlled the potential triggering of a warning when you attempted to open an Internet link within a PDF file (as Adobe explains in more detail in a support article). It had nothing to do with opening a PDF in a web browser.
After searching the web, I eventually located the relevant Adobe support article. I learned that the options for controlling these warnings were located in Safari, not Adobe Reader. Specifically, navigate to the Security section of Safari’s Preferences. Unfortunately, the Adobe article omitted the essential next step. Here it is: Click the Manage Website Settings button. From here, select Adobe Reader in the left column. Finally, assuming you want to completely dispense with the warnings (as was the case for me), select Allow Always from the When visiting other websites: pop-up menu. You may also need to click Allow for each currently blocked website.
Success. That did it for me. Honestly, without the aid of the article, I’m not sure I would have ever stumbled over this setting. [Note: Adobe is actually using a new plug-in security feature that is part of Safari]. Even so, the article left a few unanswered questions. In my testing, I saw no difference between the Block vs. Ask options nor the Allow vs. Allow Always choices. Whatever. At least I was able to dispense with the warnings.
All of this recalls another irritation I had with Adobe Reader earlier this year. It involved problems opening PDFs saved from Safari (an issue that I have mostly but still not entirely eradicated).
In the end, the best solution may be to completely uninstall Adobe Reader. Safari can open and save PDF files without Reader’s help. And, at least for me, Preview is more than adequate for viewing PDF files outside of Safari. Yup. That’s exactly what I am going to do.