Wrong DSUB size of the male connector
In my schematic I used DSUB-9_Male_Horizontal_P2.77x2.84mm_EdgePinOffset7.70mm_Housed_MountingHolesOffset9.12mm
and a friend of mine made a housing for that which ended up too small to fit the connector.
It turns out that the size of the male connector is too small in the 3D design: it's equal to the female size (7.9 mm instead of 8.3 mm) and should be fixed.
Here's a screenshot from the linked documentation (http://service.powerdynamics.com/ec/Catalog17/Section%2007.pdf or https://web.archive.org/web/20221207101422/http://service.powerdynamics.com/ec/Catalog17/Section%2007.pdf)
The other problem (less serious) is that the pins are too small. They seem to be 0.64 mm, but that seems the correct dimension for the pins that go into PCB, not for the male pins in the connector itself. The pins in the connector should be around 1 mm (in a model I downloaded elsewhere it was 1.04 mm).