We've found out that some custom arches and doors don't work well in apartments, depending on which Maxis mesh was cloned. Some functions just go missing in SimPe, and
itsdiamondeyesuniverse figured out how to fix
any door or arch after I managed to
fix one or two. With thanks and credit to itsdiamondeyesuniverse, I'm sharing it here.
Here's a simple how-to, you'll need:
- SimPe
- the extracted resources in
UpdatingArchesToWorkInApartments- a door or arch that doesn't work in an apartment (I'm using
Door_3_C from Veranka's
Thorpe Build Set for the example below.)

1. Open the file in SimPe and select the
Object Functions (OBJf) in the Resource Tree.
2. In the Resource List, sort by Instance
3. Right-click the first one (0x00041A7) to
Replace...Navigate to where you've opened the UpdatingArchesToWorkInApartments archive and select
ObjFunctions - Instance 41a7.

After you click Open, the Resource Changed window opens asking if SimPe should reload it. Click Yes.
Replace the rest of the OBJfs with the extracted resources by corresponding instance.
Save. Check it out in game.
ObjFunctions - Instance 41B2 and
ObjFunctions - Instance 41B3 are rarely used, they are for 3-tile arches and doors.