This occurred on my iMac 24"(2008) after installing Yosemite.
The same happened when I tried to launch CS6 files, and PDF's.
I saw a suggestion on the forum to reinstall Yosemite. I did and there was
no change. Any one solve this issue ?
thanks
It's usually not necessary to change any security settings, and as a rule you shouldn't.
To make a one-time exception to the security policy, follow these instructions. They apply to Installer packages and other installable items as well as applications.
Some defective software installers may fail when Gatekeeper is enabled. Think carefully about whether you really want to run such an installer. If you do, temporarily change the setting to
Allow applications downloaded from: Anywhere
When the installation is done, revert the setting.
Some applications that don't have a developer signature have been reported not to launch the first time unless Gatekeeper is disabled. The warning message from Gatekeeper is that the application "is damaged and can’t be opened." Again, think carefully about whether you want to trust the application. If you do, disable Gatekeeper as above, launch the application, and then re-enable Gatekeeper. If you still get the warning, delete the application.
Using different browsers, which I tried -makes no difference.
I also tried changing the privacy settings and there must be a bug there too on my computer. It is so weird because it will allow me to change settings - and as soon as I close the window, it reverts to the original : allow downloads from the app store only.
More importantly, these alert pops up on items that were not downloaded, but are on the computer - i.e. PDF's with preview, JPEG's with CS6
So I am still searching.
Please read this whole message before doing anything.
This procedure is a diagnostic test. It’s unlikely to solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.
The purpose of the test is to determine whether the problem is caused by third-party software that loads automatically at startup or login, by a peripheral device, by a font conflict, or by corruption of the file system or of certain system caches.
Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards, if applicable. Start up in safe mode and log in to the account with the problem. You must hold down the shift key twice: once when you turn on the computer, and again when you log in.
Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a software RAID, you can’t do this. Ask for further instructions.
Safe mode is much slower to start up and run than normal, with limited graphics performance, and some things won’t work at all, including sound output and Wi-Fi on certain models. The next normal startup may also be somewhat slow.
The login screen appears even if you usually login automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.
Test while in safe mode. Same problem?
After testing, restart as usual (not in safe mode) and verify that you still have the problem. Post the results of the test.
As per instructions - I am not disappointed !
I did try the Safe mode login and found the issue did not go away.
I did use Onyx to do an extensive "tune up". I did not download the app. from the internet - rather copied from a Mac Pro I have ( where installing Yosemite went quite smoothly so far )
I will check after the tuneup and report my findings
Try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work. The intent is to see if it is specific to one account or a system wide problem. This account can be deleted later.
I found a "back door" solution that might give the knowledgeable a clue to the issue I am having.
Rather than trying to open a file by double clicking on it as I have , be it a PDF, JPEG or downloaded app -
I went to the finder's dropdown file menu - worked my way to locating the file I want to open and by
clicking OPEN managed to launch it without a problem or error message.
That's what I asked you to do in my first comment.
I do not mean to sound unappreciative in any way, but since the "Follow These Instructions" link in the first post does not work,I am not sure what you meant by "what you asked me to do in the first comment"
For some weird reason I am not able to change the privacy settings on this iMac ( which likely effects downloaded apps).
However, I have the same issue with files that are on the iMac ( not downloaded ) and even though I found a workaround that I described in my earlier post, I am still in the dark about a straight forward solution.
the "Follow These Instructions" link in the first post does not work
It works for me. What happens when you try to load it?
preview.dmg is damaged and can't be opened.you should move it to the trash
