Flow visualization (streamline) is missing in Vapor3

VDC and data files are made using "wrfvdccreate" and "wrf2vdc" as below

> wrfvdccreate wrfout_d01_2016-07-05_06:00:00 test.vdc

> wrf2vdc wrfout_d01_2016-07-05_06:00:00 test.vdc

All is working fine, but flow visualization (streamline) does not appear in the renderer menu. Barb, contour, isosurface etc are all fine, but NO flow (attached figure)

Is it no longer supported, or my data handling misses something?

This is my Renderer menu

(I am using macOS 10.14)

Thanks for your help

Any comment will be very helpful!