Turnitin gives the error message of "This assignment does not have a valid assignment title, start date, and /or due date" when the assignment is opened.
The assignment was not properly synced by the instructor.
The instructor must complete step 9 in the Faculty Course Start Up Check List, to properly sync the Turnitin assignments and verify optional settings. In the rare chance, the instructor does not have a step 9 that matches the one below refer them to this wiki Turnitin Settings in Canvas and let them know this process must be done for all Turnitin assignments in the course.