Flash player 22.0.0.192 Mac OSX 10.6.8 Firefox 47.

Fair enough.  I've never seen anyone complain about this on Mac, which is why I was thinking Windows. 

Anyway, same diagnosis, although I'm leaning more towards a filesystem or permissions problem. 

Uninstall Flash Player - Mac:

https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html

You can check here to see if settings.sol is present after the uninstall:

/Users/username/Library/Preferences/Macromedia/Flash Player/

Instructions on running Disk First Aid to confirm that the filesystem is in a good state.  Also run "Repair Filesystem Permissions", while you're there.  Verify Filesystem Permissions will frequently return clean, but repair will still find and fix a bunch of stuff.

https://support.apple.com/en-us/HT203176

Reinstall Flash Player from here:

http://get.adobe.com/flashplayer/

If the problem persists, have you done anything that would restrict Flash Player's ability to read/write to it's configurations files?  Any non-standard configuration changes you might have made to harden the system that might be in play?  (e.g. Followed some advice online about how to restrict Flash Player's access to something?)

First things first, it would be really helpful to know what browser and operating system we're talking about:

https://forums.adobe.com/thread/1195540

That said, I agree with Chris on the diagnosis.

The one exception here would be Google Chrome, which is why I was curious about the browser.  All of the Flash Player instances on the machine share a common set of files and directories, and subsequently, security settings, except for Chrome.  Chrome bundles it's own version of Flash Player, which is encapsulated in a way that prevents it from accessing the shared files.  Security settings for Chrome are made through the web based settings manager, and the settings and global settings options under the context menu will take you out to the right pages to manage those settings.

Assuming that it's not a third-party utility in play (and history suggests that conclusion is unlikely), we're still talking about a scenario where Flash Player is unable to read or write to the main configuration file, and/or that the file is being deleted/damaged by an underlying filesystem problem or external process.

I don't have my windows machine in front of me, but I'm pretty sure that settings.sol lives here:

XP: C:\Documents and Settings\username\Application Data\Macromedia\Flash Player\

Vista and higher: C:\Users\username\AppData\Roaming\Macromedia\Flash Player\

My first recommendation would be to uninstall Flash Player, using the uninstaller here:

Uninstall Flash Player - Windows:

https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html

Then, take a quick look and see if settings.sol is still present in the above directory.  If it is, we've confirmed that the filesystem is in a bad state. The settings file is damaged and we weren't able to remove it. Since the filesystem is in a bad state, we need to solve that underlying problem before worrying about getting Flash to work.

I'd recommend that you back up anything critical, then perform some basic disk maintenance.  Disk corruption can be an early indicator of hardware failure, so backing up before you give the disk a good workout by running a scan is a wise idea.  Data recovery services are extremely expensive and easily avoidable.

Once your backup house is in order, check for and repair any problems with the filesystem:

Check your hard disk for errors - Windows 7:

https://support.microsoft.com/en-us/kb/2641432

If you still can't delete the file, there's a system utility called Unlocker for windows that usually gets the job done for me, but feel free to use whatever method you're comfortable with.

At that point, do a fresh install of Flash Player.  You can grab the latest installer here:

http://get.adobe.com/flashplayer/

If you reinstall and you're still running into this problem, I'd bet money that there's a process on your machine deleting/damaging our configuration file.  Every single time I've seen a similar complaint over the last ~9 years (and I've investigated a *lot* of them first-hand), the problem has been self-inflicted.  It's usually a snake-oil privacy utility, which confuses Local Shared Objects with our primary config file, and deletes it when removing "Flash Cookies".  This is counter-productive, as it resets the user's preferences, including any non-default security restrictions they may have added.

My next recommendation would be to explicitly uninstall any privacy tools on the machine temporarily, as a troubleshooting method.  Double-check all of your browser's plugins and add-ons, etc., to make sure there's not a utility running on exit that you might have installed and forgotten about.

If the problem goes away, install tools individually until the problem comes back.  At that point, you've identified the source of the problem.

Just for background, a lot of the fear around LSOs is largely superstition at this point, and more importantly, many of the techniques that might have helped in the past for blocking tracking are largely disproven by current academic literature.  I've explained this in detail in older posts, with links to sources, and you're welcome to look through my activity to find the relevant posts if you care.

Long story short, in response to the widespread adoption of LSOs by marketers as a clever way to add resilience to tracking cookies, we worked with the browser vendors to add APIs that tell us when the user initiates an action to clear their cookies in the browser, and we clear the LSOs as well.  It's actually been that way for years.  It's also the case that HTML5 offers a host of new ways for marketers to persist tracking identifiers that are far superior to methods that used Flash and LSOs.

In 2016, using Private Browsing / Incognito Mode is a superior approach in general to worrying about just Flash LSOs and security settings.  When Flash Player is running in incognito mode, we share a lot less information that can be used to fingerprint the machine (we report a very reduced set of fonts, as an example) to make Flash a less useful tool for server-side fingerprinting techniques, and while LSOs are stored during the browsing session, everything happens in a temporary directory that is destroyed when you exit the browsing session.

Also, when running in Incognito Mode, the Flash content generally doesn't know that it's denied from storing things like LSOs, so you can avoid setting things like "always prompt" to Local Shared Objects, and enduring the constant prompts on video and news sites.  In addition, when the browser is in Incognito mode, the browser makes similar accommodations for the HTML5 facilities commonly used/abused for tracking persistence, and you don't have to constantly blow away your history and search data.

Anyway, hopefully that's useful.  This isn't a new injection or widespread bug in Flash.  It's something specific to your local machine.  If you've diligently completed the steps above and are still having the problem, please let us know and we'll see what we can do to help.