Open Problem Library - 500 error when selecting subject or target set

Open Problem Library - 500 error when selecting subject or target set

by Walter Schwarz -
Number of replies: 1
I have ran the OPL-update script which has populated the "Subject:" list.  The script processed 36000 files, 25 subjects, 115 textbooks, and 3 statistics with a successful completion message of "Done." at the end.  However, when making a selection from the "Subject" list or the "Target Set" list via the Library Browser when browsing the "Open Problem Library" the following error appears:

WebworkClient Errors


500 Internal Server Error at /opt/webwork/webwork2/lib/ line 293.

End Errors

WeBWorK error

An error occured while processing your request. For help, please send mail to this site's webmaster (, including all of the following information as well as what what you were doing when the error occured.

Mon Jan 23 11:42:47 2017

Warning messages

Error messages

xmlrpcCall to searchLib returned no result for

Call stack

The information below can help locate the source of the problem.

  • in WeBWorK::ContentGenerator::instructorXMLHandler::content called at line 233 of /opt/webwork/webwork2/lib/WeBWorK/
  • in WeBWorK::ContentGenerator::go called at line 382 of /opt/webwork/webwork2/lib/

Request information

HTTP Headers
User-AgentMozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0
Accept-Encodinggzip, deflate
Content-Typeapplication/x-www-form-urlencoded; charset=UTF-8
CookieWeBWorKCourseAuthen.MATH-112-11-SP17=admin%09w9OGrFONT0mRrjyvjRLPTcybp4d2F82L%091485189569; _ga=GA1.2.1585775511.1472827924; __utma=104196051.1585775511.1472827924.1475524870.1475606390.5; __utmz=104196051.1473969880.3.2.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=(not%20provided)

Any suggestions on what is causing this error?
In reply to Walter Schwarz

Re: Open Problem Library - 500 error when selecting subject or target set

by Gavin LaRose -

For what it's worth, a belated reply. I was getting the same error, and looking in the web server's error log turned up the error message

Illegal field name 'APR::Table=HASH(0x7f58f28daa28)' at /usr/share/perl5/vendor_perl/SOAP/Transport/ line 801

A search suggested this was a bug with an older version of SOAP::Lite. Upgrading that module seems to have resolved the issue, though the RPC call response time is now monstrously long.