BitLocker event logs

Applies to: Configuration Manager (current branch)

The BitLocker management agent and web services use Windows event logs to record messages. In the Event Viewer, go to Applications and Services Logs, Microsoft, Windows. The log channel (node) varies depending upon the computer and the component:

  • MBAM: BitLocker management agent on a client computer
  • MBAM-Web:
    • Recovery service on the management point
    • Self-service portal
    • Administration and monitoring website

For more information about specific messages in these logs, see the following articles:

In each node, by default you'll see two log channels: Admin and Operational. For more detailed troubleshooting information, you can also show analytics and debug logs.

Log properties

In Windows Event Viewer, select a specific log. For example, Admin. Go to the Action menu, and select Properties. Configure the following settings:

  • Maximum log size (KB): by default, this setting is 1028 (1 MB) for all logs.
  • When maximum event log size is reached: by default, the Admin and Operational logs are set to Overwrite events as needed (oldest events first).

Analytic and debug logs

You can enable more detailed logs for troubleshooting purposes. In Event Viewer, go to the View menu, and select Show Analytic and Debug Logs. Now when you browse to the log channel, you'll see two additional logs: Analytic and Debug.


By default, these logs have the following properties:

  • Maximum log size (KB): 1028 (1 MB)
  • Do not overwrite events (Clear logs manually)

Export logs to text

Especially with the analytic and debug logs, you may find it easier to review the logs entries in a single text file. Use the following PowerShell commands to export the event log entries to text files:

# Out-String with a larger -Width does a better job compared to using Out-File with -Width. -Oldest is only required with debug/analytic logs.

# Debug log
Get-WinEvent -LogName Microsoft-Windows-MBAM/Debug -Oldest | Format-Table -AutoSize | Out-String -Width 4096 | Out-File C:\Temp\MBAM_Log_Debug.txt

# Analytic log
Get-WinEvent -LogName Microsoft-Windows-MBAM/Analytic -Oldest | Format-Table -AutoSize | Out-String -Width 4096 | Out-File C:\Temp\MBAM_Log_Analytic.txt

# Admin log
# The above command truncates the output from the admin log, this sample reformats the strings
Get-WinEvent -LogName Microsoft-Windows-MBAM/Admin |
    Select TimeCreated, LevelDisplayName, TaskDisplayName, @{n='Message';e={$_.Message.trim()}} |
    Format-Table -AutoSize -Wrap | Out-String -Width 4096 |
    Out-File -FilePath C:\Temp\MBAM_Log_Admin.txt