No I don't actually, that might be the problem if you guys do use it.
Excluding the crossbows is fairly easy though, just go into the notepad file that says "mod". Then just find the crossbow section and delete all the lines pertaining to crossbows. Once you have deleted all of them then just run the heirloom installer.
You will probably have to repair your game first then use the installer after you have changed the mod.txt. If you have trouble I can do it for you.