I have encountered a bug of sorts in the Essay problem sets: (PGessaymacros.pl)
Let me explain the context:
1.) I encouraged students to use LaTeX entry in their essay answers to display the greek letters of mu and alpha, aka: and .
2.) About 10% of my students opted to create these expressions in other faulty ways: that is they copy and pasted the images of mu and alpha from the web or symbol tablets, or used ALT + 981, or ALT + 224.
3.) These efforts of course resulted in very strange characters which I will NOT copy and paste here as this is the beginning of the glitch. But I am entering a LaTeX version of what one of these images looked like:
instead of there are many more variations that can't be simulated by LaTeX.
4.) So far, this is NOT the bug, just the background of how the bug gets it start. The bug comes into play when the grader, namely, me here, decides to copy and paste these images into the comment section for the student's feedback on their Essay submission. I wanted the students to see that the image that they thought would render mu or alpha is in fact a jumbled gibberish of odd characters. And can you dear student see that the copy and paste method will render something quite different than your intent. And could you please stop doing so.
5.) I save my comments in webwork after every two or three student papers. After a half-dozen saves (15-20 students) I am directed to the "Webwork Error" page and none of my recent work was saved. It was only after an hour transferring these written comments to a file for later distribution that I discovered the glitch: Those students that had their copy and pasted characters pasted into their comment feedback had hundreds and hundreds of said characters. They were replicating exponentially with every save of the comment page.
6.) Deleting all instances of these errant characters fixed the problem.
7.) Just a heads up here that the same potential problem is waiting for folks using an LTI file to enable grade-passback between webwork and their LMS. It is the copyright symbol, The Capital "C" within a circle, that is the errant character here. Yes, keep the word "copyright" in place in the LTI file you are using, but delete the circumscribed C. And do not think that because it is behind a commented ## statement that it goes unnoticed. When you save your LTI file more than a few times that circumscribed C character will generate many symbols that look like . Saving the LTI file a number of times is what one does when testing the connection of the LTI, After so many saves your attempt to access the LTI file in the file manager will be met with the pink letters: "This does not appear to be a text file". And then you can't access the LTI file. Keep a fresh copy on file, or just delete the circumscribed C.