missing wall segments along the bottom of 1st story

[DrCADD]

Along the floor-line of interior and exterior walls, I'm getting missing segments.  They appear as cutouts in random places.  When I drag the walls away from the building, the cutouts disappear and the walls are solid bottom to top.  "Clear all connections" did nothing.  Thinking that I had hidden overlapping structure, I started deleting objects to try to determine the culprit (leaving only the exterior walls).  The cutouts remained.  I'm out of ideas.  Anyone have thoughts?

Operating system used: Windows 25H2

[Patrick M · Accepted solution]

these are likely elements on hidden layers that are interacting with the walls on visible layers.
in your layer manager (com+L or document > layers), sort by layer visibility in the right column. Select all layers not visible, and set those layers to layer group 0. Group 0 does not interact with any other elements, even the same layer. It is a great strategy for isolating hidden layers and preventing them from cropping out your model like this!

make sure you update your layer combo so it's not using a random "Custom" layer combination.

...

additionally, if it helps, think of layer groups like a language barrier. Layer 0 can not communicate with anything. Layer 1 only communicates with layer 1. Layer 2 with layer 2.
My strategy is typically:
Layer Group 0 = layer is not visible for given layer combination
Layer Group 1 = Standard model elements that interact with all other model elements

Layer Group 2 = Special case elements that need to be visible with group 1, but not interact: IE barge rafters that shouldn't miter with eave fascia
Layer Group 3 = Special wall elements that can't interact with group 1 or 2: IE footings and foundation elements that can wreak havoc on belly band trim, first floor walls, rim boards, etc.
Layer Group 999 = Structural/Mechanical IFC import hotlink host layer: ensures structural beams don't get mitered/cropped by architectural trim.

[DrCADD]

Thank you, Parick!  Model restored! 🎉

[Patrick M]

make sure you update all relevant layer combos... you'll get a month down the road and need the elevations or sections too 😉