unknown component`and `Invalid property name`

hi, I just opened (on manjaro) "QT 3D : Simple QML Example", then in `simple-qml.pro` I changed `!include( ../examples.pri )` for `!include( /usr/share/doc/qt/examples/qt3d/examples.pri)` so `qmake` and the build works. I can run the application without problem. But when I look inside qml file, let say `CameraController.qml` I got many `unknown component`and `Invalid property name` in the editor (for the brave: https://i.imgur.com/gXmFOca.png)

 ok the problem doesn't seems to be about the monkey who drink beer at 1feet (30cm) of the laptop... I installed qt on ubuntu 18.04 from the qt installer (not the packages, because examples packages seems having problem...) and I got the same problem

see i.imgur.com/0Waf3Fo.png

good luck!

regards,

//Nicoo