Exchange Vows Grayed Out on wedding arch

Every time (and I mean every time) that I try to hold a custom gold wedding event on one of the Wedding venues I find that the arches do not work.  None of the options to get married are active.  They are always greyed out or they say that your wedding partner isn't around,  call them over.  Naturally they are standing right next to your other sim just waiting to get married.   However  if they just buy a wedding arch on their homelot they can always get married.  Honestly,  I don't think those wedding venues are going to stay in business very long (ha  ha  ha) because I will just have my couples go visit the neighbors that have the arch at their home and then save all that money.