No flash videos...

[SlickStretch]

I can't watch flash videos. Whenever I try to go to YouTube with Firefox, I get a black box where the video should be. If I try with Chromium, I get a puzzle piece that says "Plugin could not be loaded." I'm running Lubuntu 13.04, Firefox 20.0, Chromium 25.0.1364.160, and Flash 11.2

I'm using an older system, and I've heard that using an older version of Flash can sometimes solve the issue, but I'm really new to Linux, and I don't know how to go about it.

I've tried installing FLASH-AID but it says it's not compatible with this version of firefox...

[Resistent]

I am using a HP Compaq DC 7600 (from 2005), also Lubuntu and also Chromium. I don't have problems with Flash (not in Chromium, not in Firefox and not with Chrome),
I have the version Adobe Flash Version 11.2.202.261 (which is not the newest)
I have the Lubuntu Version 23.0.1271.97 Ubuntu 12.10 (23.0.1271.97-0ubuntu0.12.10.1)


Can u update to newer Flash Player version?