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No math displayed after upgrade to 2.15

No math displayed after upgrade to 2.15

by Larry Riddle -
Number of replies: 4

I recently upgraded our server to version 2.15. At the same time, the server was converted to a secure one using https (which we needed to use WebWorK from Canvas via LTI without Canvas complaining about trying to connect to an insecure server).

Today I noticed that no math is being displayed in any of the problems. All that is shown is [math]. I found the recent thread at https://webwork.maa.org/moodle/mod/forum/discuss.php?d=4837 about Mathjax only working in the Library Browser. In our case it is not even working there.

I looked at the reference in the earlier thread to "Configure lighttpd to use SSL" in the file about installing 2.15 on a linux server and have followed those steps. But it talks about editing the conf file in the directory /etc/lighttpd, and we don't have such a directory, so now I'm stuck.

I cannot ask our (one and only) network person for help with this because he is swamped trying to get everything ready for our campus to go to entirely online teaching in a few weeks. So can anyone walk me through how to get Mathjax working on our system so that the math expressions are displayed.

If it helps, we are a small college so do not have lots of students using WeBWorK. I would estimate a total of less than 100, not all of whom would be using it simultaneously. I saw a remark that "The other option is to set thing up so that MathJax is served by apache2". Is that a viable option for us, and if so, how do I do that?

Thanks for any help.

In reply to Larry Riddle

Re: No math displayed after upgrade to 2.15

by Danny Glin -
The first thing to check is to make sure the variable $server_root_url in site.conf has "https" at the start.
If you never set up lighttpd in the past, then that probably isn't the problem.
In reply to Danny Glin

Re: No math displayed after upgrade to 2.15

by Larry Riddle -
The change to https in $server_root_url was made when the upgrade was done. As far as I am aware, we have never used lighttpd in previous versions of WeBWorK.
In reply to Larry Riddle

Re: No math displayed after upgrade to 2.15

by Danny Glin -

If you've never enabled lighttpd then it's probably not the problem here.

Did you update MathJax when you updated WeBWorK?  If so, that's probably the problem since WeBWorK doesn't currently support MathJax 3, which is the current version.  If so, you'll need to revert to MathJax v.2:

cd /opt/webwork/MathJax

git checkout legacy-v2

If that's not the issue, the next suggestion for troubleshooting is to look at the javascript console in your browser to see what errors you get. This will depend on which browser you're using, but is probably in the "develop" menu.

In reply to Danny Glin

Re: No math displayed after upgrade to 2.15

by Larry Riddle -
Thanks, Danny. I ran the git command and it reported (but see below) that :
Already on 'legacy-v2'
Your branch is up-to-date with 'origin/legacy-v2'.

But here's the strange thing. I just tried checking some problems again to get ready to check the javascript console, and the math is now displayed correctly!!

I When I did the 2.15 updates several weeks ago, I followed the commands at

https://webwork.maa.org/wiki/Installation_Manual_for_2.15_on_Ubuntu_20.04_Desktop#Checking_for_and_Installing_Hotfixes

There is a section there about updating MathJax, so I must have run those commands. When I first tried running the git checkout legacy-v2 command tonight, I got a bunch of warnings about being unable to unlink a whole bunch of files in directory es5 with permission being denied. But at the end of the warnings it said

Branch legacy-v2 set up to track remote branch legacy-v2 from origin.
Switched to a new branch 'legacy-v2'

I then reran the git checkout using sudo, got no warnings and that was when it said we were already on legacy-v2. It was after that that I discovered that the problems were now correctly displaying the math expressions. So is it possible we actually did revert back to MathJax v.2 the first time the git command was run, even with all the warning messages?

Whatever it was that did happen, the issue now seems to hopefully be resolved. If it was indeed a MathJax issue, someone might want to revise the sentence in the Installation Manual for 2.15 that says "Updating MathJax is usually very safe".

Thanks for your help. Much appreciated.