#62 Computers occasionally (to often) hangs/freezes during exam

[Bernt Schechinger]

We at Chalmers university of technology have problems that our computers occasionally (to often) hangs/freezes during exam in Inspera with SafeExamBrowser. During a 4-hour examination approximately 5% of the computers will freeze. We don’t have that problem when the students use other software e.g. like Matlab or Word. The problem is limited to the stationary computers in our computer rooms. We don’t have the problem when he students run the examination on their own private computers.

What is it that makes that an exam student can take an old-fashioned, unattended laptop and carry out the exam in Inspera without any problems while our fairly new, patched and well-managed desktop computers risk to freeze?

A big difference is that the exam student on her/his own laptop is logged in with a local account while the exam student on the desktop computer is logged with her/his domain account. This means that all information is written locally on the laptop while the domain user has their home directory and some other folders on the network. (I was a little thoughtful when I saw that SafeExamBrowser wrote their logs in a user folder that is redirected to a network share. (It would have been good if, when installing SafeExamBrowser, you could specify where the program should write their logs))

For the desktop computers, the conditions are further complicated by different domain policies, settings that are set for the computer to work with different applications and be protected against various security threats etc. The desktop computers use the UEFI BIOS and have virtualization enabled (VT-d + VT-x) while most private computers are likely to use the legacy BIOS. Of course, any of these settings can conflict with SafeExamBrowser.

Although 5% hangs may seem like a lot, it is not easy to troubleshoot - Verification of whether an action gives any result must be done with many simultaneous users.

We hope that you with your experience might have any ideas or suggestions on what can be the cause of the problem! Bellow find information about uor computer environment and I also attach logging from four different computers that have freezed during exam.

Windows version: Windows 10 18:03
SEB version: 2.2.3 (had same problem with 2.2.1 before)
Computers: Motherboard ASUS Q170M-C
Processor Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz
Memory 8GB
Graphic card NVIDIA Geforce GTX 950’
(This is our main computer setup. We have also run some exams on other computer models and the problem exists on those also)
Symptom: Computer hangs with no possibility to enter commands from keyboard. Reboot is only solution. The hanging can occur any time during exam. The fastest hanging so far was after entering 6 characters but we have also had hangings after several hours in the exam.

Thankful for answer!
Best regards!

Bernt Schechinger
Chalmers IT-Office

[Damian Büchel]

Thanks for your detailed report. As you suggested, this appears to be an issue with your particular setup: SEB indeed has multiple log files in the %APPDATA%\Roaming\SafeExamBrowser folder of the user, and if that particular folder is located on a network location, this is most likely the cause of the issue (as writing to the logs happens very frequently).
I am not a system administrator, but if it were possible, it would certainly be better to pull the profile from the network when a user logs in to a computer, and then synchronize it again with the network once they log out. I am not aware of any BIOS settings that could conflict with SEB - however, the general rule is, as with everything: The simpler a setup, the more reliable it is.