UPDATE: This requester mailed me back and then again a week later after they found and fixed the problem! This is pretty rare and much appreciated! I tried one and it does work now. I'm having this happen a lot, one of the reasons I am getting disgusted with mTurk. I'm on a hit that allows 60min and have 40 minutes left on the clock. It said to give a brief answer to questions about images. Fine. It only took me 2 minutes to go through 10 images! Great! Now at the end and it will not submit! I've emailed the requester but this being Sunday, I'm sure I won't get a qucick response. I partly wanted to warn about this and see if anyone else is having trouble. There doesn't seem to be a work around other than hitting broken hit and going to my assigned hits (where it will still be) and hit return hit else the clock will run out and it turns into an abandoned hit. The requesters really need to test their hits out!