Mine works fine too.

Why don't you try reinstalling the add-on following the steps as shown below? (one each time)

1) Reinstall the add-on using the [REPAIR] option, or;

2) Uninstall the add-on, clean all registry data [start > regedit.exe (run as administrator) > Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\CaptainSim\ x770 and x772], restart PC and install it again, or;

3) If the problem persists, maybe your installer is corrupted.

a) Uninstall the add-on, clean all registry data [start > regedit.exe (run as administrator) > Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\CaptainSim\x770 and x772];

b) Download it again.

Check-in to Customer Support > Select product > Extended Download Service > Get New Links;

c) Restart PC and install the add-on from the new installer.

Pinatubo.