Error using TPKKV drag model

MFiX Bug report
#1

Dear MFIX team,
There seems to be a bug with the use of the new TPKKV drag model in MFIX 20.1.0. Invoking this drag model gives the error des\ drag_gp_des.f:184. However an alternative version which I coded earlier attached herewith usr_drag.f (2.8 KB) passed on as usr_drag seems to work fine.

#2

Thanks for reporting. Looks like we left it off of the DEM select case. We will fix this.
(also that user implementation you coded looks like it came from me to begin with)