The issue appears to be that all extensions bundled with Fireworks CS6 have been signed with the same certificate which has expired
Temp workaround and hardly ideal at all
1) Launch Fireworks
2) Turn your system clock back a few years
3) Launch the CSS Properties Panel
Anybody got a permanent a better fix ??
Here is a registry hack to get the disabled panels working in Fireworks CS6 :
Navigate to: HKEY_CURRENT_USER\Software\Adobe\CSXS.3
Create a string value with name "PlayerDebugMode" and value: 1
Restart Fireworks if it was already open.