I'm having exactly the same problem... It's been doing this for over a month, and I've uninstalled the plug-in, and reinstalled it more than 30 times. I'm at my wits end dealing with this.
What OS version are you using?
(>About This Mac in your menu bar)
Have you tried a "Clean Install"?
Also: http://forums.adobe.com/thread/1343084 (Illustrated and more thorough)
I have tried a clean install as well and still nothing is working.
Mount the DMG.
Right click the Flash Player installer and choose "Show Package Contents".
In Contents/Resources, double click the Adobe Flash Player.pkg
Let it run with the "Cocoa" installer.
Thanks for all these suggestions Mike, but I've done all of these steps more than a dozen times. I dont't think there's anything I can do on my end. There's definitely something not working with any of the Flash installers, and this is happening to more than 6 people I know running OS 10.8.x. I'm on 10.8.5 myself, and there's nothing that's going to make it work until Adobe discovers this problem.
I'm now unable to install this at all on my system, giving me exclamation marks on my install drives, and saying "Adobe Flash Player can't be installed on this disk." Other than the odd video that I can't play, I'm not really missing Flash, and this has been happening for over a month on my end.
Let me ask something that may seem odd.
After the 10.8.5 update, do you recall seeing a mach_kernel file in your Mac HD directory? And did you delete it?
Very interesting question... And yes, I do remember seeing that after the update. I left it there for a few weeks, and then decided to pitch it out because it seemed pretty random that there would be a stray file like that laying around on the main level of the directory.
You think this has anything to do with my problems?
I'm 100% sure it has EVERYTHING to do with it.
The mach_kernel file is a base file of your Operating system.
Apple really screwed up the 10.8.5 update in making that visible. Hundreds of thousands of people all over the world deleted it. It'll cause your problems to get worse with time.
There are two solutions... possibly three... and a "last ditch" effort to resolve this.
1. Upgrade to OS 10.9 through the App store (it's free, but not having the kernel file may prevent it. I've only seen afew cases where it did. Most people upgraded with no problems and it solved the missing mach_kernel problem for them because Mavericks installs a new one.
2. Reinstall Mt. Lion. If you have a Time MAchine, you can restoree your files, but you'll have to do a "clean install" to replace the mach_kernel file from the Installer.
3. If you have a Time Machine, you can restore the mach_kernel file from a backup. I posted instructions to do it here: http://forums.adobe.com/thread/1318151 You'll need to install a preference pane to allow you to see "hidden files", and you can restore it from the TM backup.
Worst case scenario, install the "Secrets" Preference pane. Download this zip of a mach_kernel file (mach_kernel.zip) [3.1mb] and place the zip file in your Mac HD directory. Unzip it with Stuffit Expander. You WON'T see it, unless you have hidden files shown with "Secrets".
Delete the zip file and reboot.
you should be able to install Flash Player (and other stuff) after that.
Wow, very interesting. I knew I shouldn't have pitched that file... been doing this too long to make such a rookie mistake, but I can't believe that Apple would make such a rookie mistake in making that file visible.
Any chance you can give me a good link to that 'mach_kernel.zip' file again? That link you provided above is blank, and I don't want to just grab a random one off the internet. My TimeMachine disc died a few months ago, so that's part of what I'm setting up now that I have time.
I'm not going to be upgrading to Mavericks until 10.9.2 or 10.9.3 -- I'm not going near that mess until they're finished writing it. I know more than a few people that are pulling their hair out with Mavericks problems.
Thanks so much for all this.
Okay Mike, this worked perfectly for me. Thanks again for all your help. Should have come here to the forums a few weeks ago, I can't tell you how many hours I've put into trying to fix this on my own. Have a great evening!