SEB3 service fails to start

IMPORTANT Please always consult the documentation first before creating a bug report! https://safeexambrowser.org/windows/win_usermanual_en.html

Describe the Bug On some computers SEB3’s service fails to start due to exception: “Failed to start communication host for endpoint ‘net.pipe://localhost/safeexambrowser/service’ within 5 seconds” This happens on some desktops / laptops regardless of hard drive type (HDD or SSD) when they start up.

Steps to Reproduce Steps to reproduce the behavior: It’s random behavior.

Expected Behavior SEB3’s service should implement some retry logic to ensure service is up and running.

Screenshots If applicable, add screenshots to help explain your problem.

Version Information

• OS: Windows 10 Professional, Version 1809
• SEB-Version SEB 3.0.1.163

Additional Context The only workaround was to create an automated scheduled task (attached to specific event) that tries to start SEB’s service within next 30 seconds. If interested, here is event filter:

<?xml version="1.0" encoding="UTF-8"?>
<QueryList>
   <Query Id="0" Path="System">
      <Select Path="System">*[EventData[Data[@Name='param1'] and (Data*='Safe Exam Browser Service')]]
and
*[System[(EventID='7034')]]</Select>
   </Query>
</QueryList>

Having this event filter you can deploy a scheduled task (in case you use Active Directory). Unfortunately this is not viable solution for student’s computers.

Here is service’s log:

2020-09-14 11:17:43.989 [04] - INFO: Initiating startup procedure...
2020-09-14 11:17:44.426 [04] - INFO: Starting auto-restore mechanism...
2020-09-14 11:17:44.755 [04] - INFO: [AutoRestoreMechanism] Started auto-restore mechanism.
2020-09-14 11:17:44.973 [04] - INFO: Starting communication host...
2020-09-14 11:17:45.208 [05] - DEBUG: [FeatureConfigurationBackup] No backup data found under 'C:\windows\system32\config\systemprofile\AppData\Local\SafeExamBrowser\Backup.bin'.
2020-09-14 11:17:45.270 [05] - INFO: [AutoRestoreMechanism] Nothing to restore, stopped auto-restore mechanism.
2020-09-14 11:17:49.207 [07] - DEBUG: [ServiceHost] Communication host is opening...
2020-09-14 11:17:53.910 [07] - DEBUG: [ServiceHost] Communication host has been opened.
2020-09-14 11:17:53.910 [07] - DEBUG: [ServiceHost] Successfully started communication host for endpoint 'net.pipe://localhost/safeexambrowser/service'.
2020-09-14 11:17:55.472 [04] - ERROR: Caught unexpected exception while performing operation 'CommunicationHostOperation'!

   Exception Message: Failed to start communication host for endpoint 'net.pipe://localhost/safeexambrowser/service' within 5 seconds!
   Exception Type: System.ServiceModel.CommunicationException

   at SafeExamBrowser.Communication.Hosts.BaseHost.Start() in C:\Users\appveyor\projects\seb-win-refactoring-l9ysdqd7kes2i06p\SafeExamBrowser.Communication\Hosts\BaseHost.cs:line 142
   at SafeExamBrowser.Core.Operations.CommunicationHostOperation.Perform() in C:\Users\appveyor\projects\seb-win-refactoring-l9ysdqd7kes2i06p\SafeExamBrowser.Core\Operations\CommunicationHostOperation.cs:line 42
   at SafeExamBrowser.Core.OperationModel.OperationSequence.Perform() in C:\Users\appveyor\projects\seb-win-refactoring-l9ysdqd7kes2i06p\SafeExamBrowser.Core\OperationModel\OperationSequence.cs:line 108

2020-09-14 11:17:55.488 [04] - INFO: Stopping communication host...
2020-09-14 11:17:55.488 [04] - DEBUG: [ServiceHost] Communication host is closing...
2020-09-14 11:17:56.082 [04] - DEBUG: [ServiceHost] Communication host has been closed.
2020-09-14 11:17:56.082 [04] - DEBUG: [ServiceHost] Terminated communication host for endpoint 'net.pipe://localhost/safeexambrowser/service'.
2020-09-14 11:17:56.082 [04] - INFO: Stopping auto-restore mechanism...
2020-09-14 11:17:56.082 [04] - INFO: [AutoRestoreMechanism] Auto-restore mechanism is not running.
2020-09-14 11:17:56.097 [04] - INFO: Service startup aborted!

[dbuechel]

We will increase the timeout for the service communication host to 15 seconds for version 3.1.

[dbuechel]

I think we could increase it to 10 or 15 seconds, @danschlet ? What I would like to avoid is that users are stuck in front of a loading screen for a long time if something fails.