Hello Terry, I am just a Ph.D. student, but I was able to use Turnitin integrated into Canvas (another learning management platform) and perfectly collected data from a total of 87 students. My opinion is that, yes, there are problems. However, it's important to know where they are coming from, because they not always come from Turnitin. In my experience, I was able to solve half of the problems by telling students to use an appropiate browser, such as Chrome or Firefox, as opposed to Safari or Internet Explorer. For some reason Chrome just worked wonderfully. If student still experienced problems, I would go to my second suggestion. I would tell them to log out from the learning management system (Moodle, Canvas) and then log in again. Remember that Turnitin is integrated as an external tool. That means that when students have the platform open for too long, it's likely that the connection between Turnitin and Moodle gets interrupted. This is not Turnitin's fault, it happens with any external tool you try to use. Third, if students still experience problems after logging out and logging back in the next thing I would tell them to clear 'Cache and Cookies' from their computers. This is the link I would normally give to students https://its.uiowa.edu/support/article/719 . After giving indications, I literally had 0 problems using Turnitin in the classroom. It's all a matter of paying attention, and once students were aware of how it worked, it went pretty smooth for the rest of the semester. Hope it helps for another semester!

I forgot to mention, for those using Canvas, check out the Blog https://turnitin.forumbee.com/t/63jshk/calling-all-canvas-users

Turnitin is finally within Canvas and doesn't need to be integrated as an external tool anymore! This are great news :) :) 

Enrollment key should given at beginning of class or entered at  class start.