Flashgames don´t work, Flash Player 19.0.0.226

After updating both Firefox to version 41.0.2 and Flash Player to 19.0.0.226 onlineflashgames, e.g. here

http://stronghold-world.forumo.de/arcade.php?mode=play&g=57 no longer work. All onlinegames of that forum can´t detect Flashplayer in my browser any more and state that they need at least Flash Player 8 to work. The Flashplayer test page https://helpx.adobe.com/de/flash-player.html however states that version 19.0.0.226 installed and works fine. Before the update I was using the last version of Flashplayer from the 18 series and Firefox 41.0.1 and those games worked fine.

Edit: I already tried to empty the cache of Firefox and to reload the games page but nothing changed. OS is Windows XP 32bit