In D365 Project Operations if you add a lookup to the "Project Task" table on any form, the "Look for...." dialogue box offers the option create a "+New Project Task" by opening the classic D365 Project Task form.

This should be removed/hidden from that dialogue as the user within D365 Project Operations should only create new project tasks from the Project Task Grid.

This would improve the user experience as also the error message that comes up when the user tries to create a Project Task from there from the Project Task form is quite technical and cannot be adjusted