Thank you! I was using this plugin with (the good old) October 1 and was amazed at how good it worked. What I currently tried is to set the values of resource "someModel.php" in the function " public function toArray($request)" programatically.
public function toArray($request)
'id' => id,
'active' => active,
'name' => name,
'slug' => slug,
but the error still occurs.
I also tried to fix the file permissions but the permissions were already correct.