[SOLVED] CI4 Entity using datamap to Model-Save

Did you create an Entity folder in the app folder?
If you did then you access them like this.

PHP Code:

// change this
protected $returnType = ActivityEntity::class;

// to this
protected $returnType = 'App\Entities\ActivityEntity::class';

// change this
$newActivity = new ActivityEntity();

// to this
$newActivity = new \App\Entities\ActivityEntity(); 


Also did you setup the Entity to use the correct get and set methods?

...Oh, I think I found the problem.
User guide and $datamap comment tell me:

PHP Code:

$datamap = ['db_name' =>'class_name']; 


But it should actually be:

PHP Code:

$datamap = ['class_name' =>'db_name'];