We have just received the following message from Turnitin.
You may have experienced issues viewing submissions within the Feedback Studio. This was down to a service disruption affecting the performance of Turnitin and Turnitin UK.
The service was affected between 8 and 10.40 this morning.
NOTE: They advise that you clear the cache before re-trying to mark work.
Stay up to date with Turnitin system status by following @TurnitinStatus on Twitter.