I FOUND IT.
I FOUND THE MISTAKE YAYYYYYYY
Somehow this is setted in kicad:
${KICAD8_3DMODEL_DIR}/Package_QFP.3dshapes/TQFP-144_20x20mm_P0.5mm.wrl
( maybe some prefix or so. )
I changed it to
${KICAD_3DMODEL_DIR}/Package_QFP.3dshapes/TQFP-144_20x20mm_P0.5mm.wrl
and then clicked on the Browse icon… BAAAAAM the model there.
I just removed the 8 from the VAR name.
MAybe in the Program define aliases:
define KICAD8_3DMODEL_DIR = KICAD_3DMODEL_DIR
I hope the info helps.
I tested it by opening example project kit_dev_coldfire…
I was wondering why only the plug and the switch and the tactile buttons had 3D models…
So i did investigate. FOUND IT.
a short grep -rnw -e “KICAD_3DMODEL_DIR” did give back nothing
but a -e “KICAD8_3DMODEL_DIR”
/kicad/common/settings/settings_manager.cpp:633: wxT( “KICAD8_3DMODEL_DIR” ),
and a lot of stuff from the examples.
so i did look there:
const std::vector<wxString> libKeys = {
wxT( "KICAD6_SYMBOL_DIR" ),
wxT( "KICAD6_3DMODEL_DIR" ),
wxT( "KICAD6_FOOTPRINT_DIR" ),
wxT( "KICAD6_TEMPLATE_DIR" ), // Stores the default library table to be copied
wxT( "KICAD7_SYMBOL_DIR" ),
wxT( "KICAD7_3DMODEL_DIR" ),
wxT( "KICAD7_FOOTPRINT_DIR" ),
wxT( "KICAD7_TEMPLATE_DIR" ),
wxT( "KICAD8_SYMBOL_DIR" ),
wxT( "KICAD8_3DMODEL_DIR" ),
wxT( "KICAD8_FOOTPRINT_DIR" ),
wxT( "KICAD8_TEMPLATE_DIR" ),
// Deprecated keys
wxT( "KICAD_PTEMPLATES" ),
wxT( "KISYS3DMOD" ),
wxT( "KISYSMOD" ),
wxT( "KICAD_SYMBOL_DIR" ),
};
well… go for the hunt… Oh i see settings window…
there was then also a surprise.
Only the KICAD9 were there but not all. only 2 were correctly setted…
anyway. continuing playing around till it breaks 
Hope this helps so far.
MAny greetings
