On occasion a worker may have completed a study but was unable to successfully submit the assignment for a variety of reasons (timeout, system hiccup, computer shutdown). Workers will often contact the Requester and ask for compensation for their work.
Researchers are encouraged to follow up with the workers and open a special HIT specifically for them by using our "compensation HIT" feature from the manage workers tab on the main menu bar.
Sadly, Amazon Mechanical Turk does not provide any other mechanism to pay workers who were unable to submit their assignments.
Alternatively, if this worker took a study for you in the past, you can grant the worker a bonus from that completed study from the TurkPrime dashboard.