Pls check the page access of your page.
can you share your domain model, microflow and page please?
Did you let Mendix generate the entity that is being mapped? The default generated entity is non-persistant.
Datagrids can’t retrieve non-persistent objects, because those are not committed to the database.
It will be good idea to create another persistable object with attributes that you want to show, and then copy data that you want to show from these NP objects to newley created persistable object.
Data grid cannot retreive/show NP objects, since they are not commited to database, as Roy already mentioned
you can set the “root” as input parameter of the page. Then retrieve the data over association in the datagrid.