I finally got the problem set:
openDate = 02/02/2014 at 11:59pm CST
dueDate = 02/11/2014 at 11:59pm CST
answerDate = 02/12/2014 at 11:59pm CST
paperHeaderFile = defaultHeader
screenHeaderFile = defaultHeader
Library/Rochester/setVecFunction2Curvature/ur_vc_4_5.pg, 1, -1
Library/Rochester/setVecFunction2Curvature/ur_vc_4_1.pg, 1, -1
Library/Rochester/setVecFunction2Curvature/ur_vc_4_2.pg, 1, -1
Library/Rochester/setVecFunction2Curvature/ur_vc_4_4.pg, 1, -1
Library/maCalcDB/setVecFunction3Motion/ur_vc_4_8.pg, 1, -1
Library/maCalcDB/setVecFunction2Curvature/ur_vc_4_3.pg, 1, -1
Library/Rochester/setVecFunction3Motion/ur_vc_4_7.pg, 1, -1
Library/ASU-topics/setCalculus/stef13_4p1.pg, 1, -1
Library/FortLewis/Calc3/17-2-Motion-velocity/HGM4-17-2-06-Motion-velocity-acceleration.pg, 1, -1
Library/ASU-topics/setCalculus/stef13_4p2.pg, 1, -1
Library/Dartmouth/setMTWCh4S2/problem_5.pg, 1, -1
Library/272/setStewart13_3/problem_5.pg, 1, -1
Library/Dartmouth/setStewartCh14S3/problem_3.pg, 1, -1
This is really strange problem for us. It worked ok at first. Then suddenly it stopped working. For quite some time, some users could still do that homework set while some other could not. From the system log, I can see that the first error came up when some student started doing the problem 7. This problem set file is not available from the course directly any more. Blake has a backup. My guess is that some problem(s) in this set might cause the problem under some very specific condition and we were the lucky winner.
When I first checked the problem, I found that there were some problems with the database. The corresponding table should be math233spring2014_problem_user. When I use mysqlcheck command, it looks like it fixed the problem. At least it does not report any database problem any more. But the error message from webwork is still there.
Can someone look into this strange problem?