When VIVI race is used together with Hull Style: NANAME Walls, a duplicate ThingDef error occurs on game load:

Adding duplicate Verse.ThingDef name: VV_SmoothedViviCreamWall_NAWDiagonal
Verse.DefDatabase`1.Add(Verse.ThingDef def)
RimWorld.DefGenerator.AddImpliedDef(...)
NanameWalls.GenerateDefs.GenerateInner(...)
NanameWalls.GenerateDefs..cctor()

Cause:
Both VIVI race and Naname Walls create a diagonal version of VV_SmoothedViviCreamWall using the same def name (VV_SmoothedViviCreamWall_NAWDiagonal). This leads to a hard duplicate def error on load.

Suggested fix:
In VIVI race, before adding a diagonal wall def, check if the def name already exists:

if (DefDatabase<ThingDef>.GetNamedSilentFail("VV_SmoothedViviCreamWall_NAWDiagonal") == null)
{
// add your def
}

Or alternatively, provide a mod setting to disable diagonal generation if another mod already adds it.

Thank you for the mod.