Unhandled exception during GetFVF

Hello experts,

I'm pretty new to DirectX and Direct3D so it's all still a bit confusing.
I've been given a pre-made "engine" that can easily create and transform several shapes.

When I make a box or teapot it works but when I make anything else I get an unhandled exception in the Draw function of the Mesh at m_pDXMesh->GetFVF()

Anyone have any ideas?
Thanks in advance.

void MeshShape::Init()
{
	//default material color is white
	SetMaterialColor(1,1,1,1);
 
	switch(m_Type)
	{
	case BOX:
		D3DXCreateBox(GETDEVICE,m_a,m_b,m_c,&m_pDXMesh,0);
		break;
	case SPHERE:
		D3DXCreateSphere(GETDEVICE,m_a,(UINT)m_b,(UINT)m_c,&m_pDXMesh,0);
		break;
	case TEAPOT:
		D3DXCreateTeapot(GETDEVICE,&m_pDXMesh,0);
		break;
	case TORUS:
		D3DXCreateTorus(GETDEVICE,m_a,m_b,(UINT)m_c,(UINT)m_d,&m_pDXMesh,0);
		break;
	case CYLINDER:
		D3DXCreateCylinder(GETDEVICE,m_a,m_b,m_c,(UINT)m_d,(UINT)m_e,&m_pDXMesh,0);
		break;
	default:
		D3DXCreateBox(GETDEVICE,1,1,1,&m_pDXMesh,0);
	}
}
 
void MeshShape::Draw() 
{
    GETDEVICE->SetMaterial( &m_Mtrl );
	GETDEVICE->SetTransform( D3DTS_WORLD, &m_FinalWorld );
 
        // THIS LINE GIVES UNHANDLED EXCEPTION
	GETDEVICE->SetFVF( m_pDXMesh->GetFVF() ); 
	m_pDXMesh->DrawSubset(0);
}
 
 
 
void MultiMeshBasisApp::BuildScene()
{
	// This works
	m_pFloor = new MeshShape(MeshShape::BOX,10,0.1f,10);
	m_pFloor->SetMaterialColor(0.6f,0.6f,0.6f,1.0f);
	m_pFloor->Translate(0,-2,4);
	m_pFloor->Draw();
	
 
	// This works too
	m_pTeapot = new MeshShape(MeshShape::TEAPOT,1.0f,2.0f,1.0f);
	m_pTeapot->SetMaterialColor(1.0f,1.0f,0.1f,1.0f);
	m_pTeapot->Translate(3.0f,0.0f,6.0f);
	m_pTeapot->Draw();
 
	// This doesn't
	m_pCylinder = new MeshShape(MeshShape::TORUS,1.0f,2.0f,1.0f);
	m_pCylinder->SetMaterialColor(0.05f,0.2f,0.9f,1.0f);
	m_pCylinder->Translate(0,0,0);
	m_pCylinder->Draw(); // <- Here's the problem
 
}

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