I’ve been running an experiment on Mechanical Turk. I have several different versions of the same HIT that I’ve been using for months with no problems. I don’t direct workers to a different website or server… my code is running within MTurk. But suddenly, starting last week, workers can no longer submit my HITs. Instead of the HIT just running in the browser like it’s supposed to, clicking the Accept HIT button downloads an HTML file. If a worker opens the downloaded file and runs through the task, they are unable to submit it.