Safe Exam Browser won't start for some students

Safe Exam Browser won't start for some students

by Nikolaas Dries -
Number of replies: 7

Hello everyone

Problem
For some students, SEB will not start when they click 'start safe exam browser' in a moodle quiz.
We are using the manual config in Moodle, where Moodle generates the SEB file and starts the SEB browser with this file.

This is what I see in the Moodle quiz logs:
The user with id '2082' has been prevented from accessing quiz with id '6183' by the Safe Exam Browser access plugin. The reason was 'Ongeldige SEB configuratie sleutel.'. Expected config key: '85ce3a1f6e0804c4e2ecda3d2156725dcba2d8d72baa43982e777d9d69bc6717'. Received config key: ''. Received browser exam key: ''.

Ongeldige SEB configuratie sleutel = invalid SEB configuration key
image

Situation
I've got this problem with, on average, 20 out of 550 students. The problem wasn't visible during the regular lesson period, because quizes were organized per class. Right now we're doing exams with up to 200 students at the same time.

Background information

  • SEB version 2.4
  • 600 identical laptops, same batch from factory. So, hardware is as identical as it can be.
  • Image provided by external company. SEB is included in image.
  • Windows Defender as AV on laptop
  • Fortigate as network firewall

I've tried

  • I contacted our Moodle host. They say that this is a problem with the configuration of the laptops.
  • I contacted our external laptop partner, since they provide us with the image. They say VC++ sometimes doesn't get installed the right way when deploying the image. I've been able to test manually installing this on one computer. No succes.
  • I've tried removing and installing the latest version of the SEB. No succes.
  • I've reimaged the computer: about 70% succes rate.

I would be very grateful if someone could explain what this config key is about. Why would this continue to be a problem after reinstalling the SEB?
Any other advice on what to look at, do or test is also greatly apreciated.


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In reply to Nikolaas Dries

Re: Safe Exam Browser won't start for some students

by John Provasnik -
Picture of Particularly helpful Moodlers Picture of Testers
Hi Nikolaas - I've only started to use Safe Exam browser at my school. my understanding is that before students click "Launch Safe Exam Browser" in the quiz, they first need to click "Download configuration" - I could be wrong but do you know if all studnets are performing the same set of actions prior to attempting to launch the quiz??
Attachment sebquiz.png
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In reply to John Provasnik

Re: Safe Exam Browser won't start for some students

by Nikolaas Dries -
Yes, I know. They are watched by teachers.
When I use download config they get into a loop where they try to start the SEB within the SEB because the button 'launch safe exam browser' is still there.
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In reply to Nikolaas Dries

Re: Safe Exam Browser won't start for some students

by Marco Lehre -
Picture of Testers
Hi Nikoolas, the config key is a hash of the SEB configuration. Moodle is able to calculate the config key with your manual SEB config that you have made on Moodle. SEB always sends the config key of the configuration it has. When SEB tries to access a Moodle test, Moodle checks if the config key that SEB sends matches the config key of the manual configuration in Moodle. Moodle denies access to the test in the case the two config keys do not match.
I propose to try the "Download configuration" button. Download the file and open it by doubleclicking. SEB will start in the correct configuration.
Do the problems persist?
Another idea would be that the students navigate to the quiz with SEB (the local SEB config should have the URL of your Moodle as starting URL). When the students reach the start page of the test in Moodle, SEB will reconfigure automatically (if the option "Auto-configure SEB" is activated in the Moodle-Admin section). This is the most comfortable way to use SEB. No download of a config, no launch of SEB on the test start page is needed any more.
There is a bug in using the "Launch Safe Exam Browser" button together with certain configurations, i.g. using of SEB with two or more displays.
The bug will be fixed in SEB Win v. 3.3.2 .
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In reply to Marco Lehre

Re: Safe Exam Browser won't start for some students

by Nikolaas Dries -
Thanks for the tip. I'll test this method.
I've found my solution for now, I'll post it in a reply to my start post. This might be easier for others to find the answer.
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In reply to Nikolaas Dries

Re: Safe Exam Browser won't start for some students

by Jon Witts -
Picture of Particularly helpful Moodlers Picture of Plugin developers Picture of Testers
When using SEB I set up links on the student's desktop to the exam with a URL like this:

sebs:///mod/quiz/accessrule/seb/config.php?cmid=
My students then just click the link and SEB launches and takes them straight to the quiz... This is done with the manual SEB configuration inside the Moodle quiz too
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In reply to Jon Witts

Re: Safe Exam Browser won't start for some students

by Nikolaas Dries -
Thanks voor the reply. I think this won't work for us because we have too many different examens going on at the same time.
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In reply to Nikolaas Dries

Re: Safe Exam Browser won't start for some students

by Nikolaas Dries -
Hello all

The solution was given below. I reinstalled with the newest version of SEB. My previous tests in september were with an earlier version.
Thanks everyone.
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