flash player not working
This (general installation error) is because you inadvertently (or naively) deleted the mach_kernel file that appeared in your Mc HD directory after the 10.8.5 update.
If you have a TIme Machine and use the "Secrets" pereference pane to reveal "hidden files", you can restore it from a "pre 10.8.5" backup.
Otherwise, you've got to reinstall your operating system.
There are no two ways about it, and there is no workaround other than what I described above.
I keep getting the message "blocked plug in "
This usually means some parts of an older Flash Player version remains on your machine.
Perform a clean install: How to perform a "clean install" of Flash Player in Mac OS X
which file? what's its name? how to show it from an old backup (timemachine)?
secrets pref are very dangerous and which check box do we need to turn on or off?
maybe updating to os mavericks everything will be back in order to work?
Upgrading to Mavericks may or may not work. I haven't seen anyting that indicates it won't if the mach_kernel is missing.
Follow the instruction here: http://forums.adobe.com/message/5772637#5772637
They worked in JUST A FEW MINUTES for that poster.