JAE_LY20-16P-DLT1_2x08_P2.00mm_Horizontal.wrl is missing,
SW_SPST_CK_KXT3.wrl is missing,
SOP-8_3.9x4.9mm_P1.27mm.wrl is missing and
Jack_3.5mm_PJ320D_Horizontal.wrl is missing.
where can i get those 3D-Models?
JAE_LY20-16P-DLT1_2x08_P2.00mm_Horizontal.wrl is missing,
SW_SPST_CK_KXT3.wrl is missing,
SOP-8_3.9x4.9mm_P1.27mm.wrl is missing and
Jack_3.5mm_PJ320D_Horizontal.wrl is missing.
where can i get those 3D-Models?
Either from the manufacturers or make your own . . .
I Don’t know why
The reason why some footprints are missing in the kicad library is explained in this FAQ article: Why a footprint points to a 3D model but the model file doesn't exist?
regarding your specific mentioned footprints:
I was Engineering Director (and Sr. Design Engineer) for a US division of JAE. At the time, years ago, we only made files available for products with sufficient sales volume. We designed and produced far too many that did not pay for the added labor/effort…etc.
And, many are too old and were not designed with current CAD software. I don’t know about the particular item you cited so, you may be able to get it…