I got this too after installing 1.5 u-boat addon. I completely uninstalled both and went into C://program files/UBI and deleted the UBI folder. Some stuff can be left in there even after un-installing the game that can interfere with a re-install. I then re-installed SH4 and the U-boat addon. After I did that it ran like a champ!
Also, there is no need to patch if you are installing the u-boat addon. Just do a clean install of SH4 vanilla and then U-boat.
Hope that helps.
Cheers