Recently, we moved our webwork to Ubuntu. It has been running fine until today. There are some problems with a particular homework set. In the early morning today, I was told that there are some problems with a particular homework set. At first, I couldn't log in as admin. Then I found out that there was some problem with the corresponding mysql *_problem_user table. After I used mysqlcheck command to get that fixed, for some user, it works fine. But for admin and some other users, it is still not working. For example, if I log on as admin and click that particular homework set "WW3", I would get the following error message:
Can't call method "flags" on an undefined value at /opt/webwork/webwork2/lib/WeBWorK/ContentGenerator/ProblemSet.pm line 358.
The information below can help locate the source of the problem.
in WeBWorK::ContentGenerator::ProblemSet::body called at line 152 of /opt/webwork/webwork2/lib/WeBWorK/Template.pm
in WeBWorK::Template::template called at line 509 of /opt/webwork/webwork2/lib/WeBWorK/ContentGenerator.pm
in WeBWorK::ContentGenerator::content called at line 200 of /opt/webwork/webwork2/lib/WeBWorK/ContentGenerator.pm
in WeBWorK::ContentGenerator::go called at line 370 of /opt/webwork/webwork2/lib/WeBWorK.pm
I searched the forum. It seems that I did not find anything related to that "can't call method "flags" on an undefined value".