adobe flash player won't install on safari 10.6.8

I have uninstalled adobe, cleared the downloads in finder, reinstalled adobe, and cleared the cache, cookies in safari.

Adobe won't run in Firefox either.

Correction: I can install adobe flash player on both safari and firefox, but when I try to play a youtube video, I get a message saying I have to install adobe flash player. I don't know what else to do.

Lastly, some forms won't open when I click on them. I get a dark grey page.