Zkus ho kompletne odinstalovat:
http://download.macromedia.com/get/flashplayer/cur rent/support/uninstall_flash_player.exe
restartnout PC a stahnout offline instalaci flash ze stranek Adobe:
https://www.adobe.com/cz/products/flashplayer/dist ribution3.html
Predpokladam, ze nemas nejake blokovani doplnku atd...