I came across this event on an Exchange 2013 CU9 server which I was configuring for a customer.
Searching for solutions to this event made me understand that this is something that’s been going on since Exchange 2013 Cu7. The fix is quite simple and does not have any impact on the Exchange system.
Simply disable the Bitlocker check on the drive where diagnostics root directory exists.
Open below file in notepad (run as admin):
C:\Program Files\Microsoft\Exchange Server\V15\bin\Microsoft.Exchange.Diagnostics.Service.exe.config
Change the parameter “DriveLockCheckEnabled” value=”True” to “DriveLockCheckEnabled” value=”False” and save the config-file.
<!– Settings used when checking Bitlocker state of the drive where the diagnostics root directory exists –>
<add key=”DriveLockCheckEnabled” value=”False” />
<add key=”DriveLockCheckInterval” value=”00:00:10″/>
<add key=”DriveLockMaxDuration” value=”00:04:00″/>
Restart MicrosoftExchangeDiagnostics service, and the error message is gone.