Q: Opening .pdf files with Preview - Gatekeeper says: xxx can't be opened because it is from an unidentified developer
As above, Gatekeeper displays the message: ['FileName'.pdf] can't be opened because it is from an unidentified developer.
This only started happening after I changed the default programme to open .pdf files from Adobe Reader to Preview (serious speed issues with Adobe) - using the 'Open with' > 'Always Open With' option.
This is clearly a Gatekeeper action as appropriate for the "Mac App Store and identified developers" Gatekeeper option setting in System Preferences - EXCEPT this normally applies to apps and not individual files!
I could do all the usual right-click Open options to override it but I found it only applied to that individual .pdf file and when opening another I would get the same dialogue popup. This Gatekeeper behaviour only applies to .pdf file recently downloaded from the Internet it seems and pre-existing .pdf files open normally with Preview no problem.
I have temporarily overcome this by downgrading the Gatekeeper security settings to 'Anywhere' but this is not a proper fix - does anyone have any ideas about this?
Thanks
MacBook Pro, OS X El Capitan (10.11.2), MacBook Pro (15-inch, Late 2011)
Posted on Jan 4, 2016 3:18 AM
Before I got your reply I applied the latest 10.11.2 combo updater but that didn't seem to fix it even though it went through the various system checks and restarts etc.
Then I saw your message and so I restarted in Safe Mode, restarted in normal mode - everything very slow to start but got there in the end.
Have reset the Gatekeeper settings back to "Mac App Store and identified developers" and tested I still getting the following symptoms:
- When I try to open a newly downloaded .pdf Preview starts up but I get this:
- Other .pdfs that I have previously permitted as safe will open OK with Preview
- Some of the .PDF files on my Desktop show Adobe PDF icons and some sow the Preview PDF preview of the file for the icon - like the above file for example but this does not appear to affect behaviour, it just seems to be another anomaly
- When I download a .pdf I get this which oddly seems to show Adobe Reader as the default:
- When I double-click on the downloaded file in the downloads folder, which has an Adobe icon, it opens with Adobe Reader
- When I make a copy of it and paste it on the desktop it saves with a Preview icon but still opens with Adobe Reader
- Then I noticed that the 'Open with' option in the properties of the two different files were different as below:
- After doing the 'Change All' thing the system seems to be returned to normal functioning as far as opening .PDF files with Preview goes...
Posted on Jan 4, 2016 9:43 AM


