Errors using Essay Problems

Errors using Essay Problems

by Jim Fischer -
Number of replies: 2
We are using WW 2.7. At first everything was fine, essay questions were behaving normally. Then our ITS department made some adjustments and now we are getting the following error(s) using essay problems. ITS is trying to retrace their steps, but I thought I would post this in case someone could save us some time, or in case someone can use this information because they are getting the same errors.

The essay problems open up fine. However, after typing some text and hitting the submit answer button, we get the following errors:

WeBWorK Warnings

WeBWorK has encountered warnings while processing your request. If this occured when viewing a problem, it was likely caused by an error or ambiguity in that problem. Otherwise, it may indicate a problem with the WeBWorK system itself. If you are a student, report these warnings to your professor to have them corrected. If you are a professor, please consult the warning output below for more information.

Warning messages

  • Error in Answer AnSwEr0002: |asdfadf|
  • Can't locate object method "new" via package "HTML::Scrubber" (perhaps you forgot to load "HTML::Scrubber"?) at line 61 of (eval 4280)
  • Error in Answer AnSwEr0002:
  • Answer evaluators must return a hash or an AnswerHash type, not type || at /opt/webwork/pg/lib/WeBWorK/PG/ line 1232
  • Use of uninitialized value in addition (+) at (eval 4239) line 1708.

Request information

Time Tue Oct 08 14:06:49 2013
Method POST
URI /webwork2/Introduction_to_WebWork/HW1_Introduction_to_WebWork/18/

In reply to Jim Fischer

Re: Errors using Essay Problems

by Michael Gage -
We've had several problems with HTML::Scrubber.  It was originally installed to help reduce the problem of XSS (cross site scripting) exploits, but it causes difficulties of its own.

It was removed from the master branch via a "hotfix" on Sept 11.  I suggest that you  have your IT people update their software from github

git pull

will work if they are tracking the master branch at -- which is the default.

Then reboot.  The HTML::Scrubber cpan module will no longer 
be required and your error message would go away.

You can view the commit process at:

The other solution is to install the HTML::Scrubber 
cpan module which will solve your error above. However, you may still find 
other glitches caused by the HTML::Scrubber. In its attempt to 
prevent evil entries it sometimes removes perfectly good input.

In reply to Michael Gage

Re: Errors using Essay Problems

by Jim Fischer -
Its been awhile since I created this thread.  I did a git pull over the winter break (WW 2.7) and still have the same errors when trying to use essay problems. Something to do with HTML Scrubber

The process seemed to work, I was able to update the WW system and the problem library, reboot etc.

Is there something else I can do to track down the problem I'm having with our installation with respect to essay problems? Maybe when I run  the git pull Im doing something wrong?  

The problem Im testing with is from the templates area of the Wiki. Specifically: