Thank you very much for the quick reply and for pointing me in the right direction. I am also very sorry for not getting back sooner.
Sorry for the confusion, I believe I have accessed the correct sever.log file this time. For some reason, the server.log file was extremely long, so I took a "snapshot" of the first 15 lines in addition to the last 15 lines:
I believe that last couple of lines of this file are the most useful. Specifically, it seems like I am missing thanks-mturksubmit.html and closepopup.html. It seems like adding these files to the psiturk-example experiment should help.
As a side note, I noticed that I am not able to access files and folders (e.g., psiturk-example) that I create in Ubuntu. I think this has more to do with Windows and Linux, and I will work on figuring this out in the mean time.