This issue has been resolved: Please update your game to 5.32 Downtown High School.
The Wedding Belles grand prize (house template) appears to have a graphical issue when built on Mysterious Island. The incorrect fence is in place and the ceremony items, front garden, backyard and river are missing.
What's causing this?
The Wedding venue template doesn't fit lots on Mysterious Island.
What can be done?
Avoid building the Wedding Belles grand prize on the Mysterious Island. Instead, try building in SimTown. If you purchased the template after July the 20th it should not be broken. Please contact support if you are experiencing issues.