Problem Description
The Druva inSync Client (version 7.5.7) was installed on a Windows machine but failed to display the login window. Although the application appeared in the system tray and ran in the background, clicking the icon produced no response. A full clean uninstall and reinstall (including removal of program files, AppData, and registry keys) did not resolve the issue. Additionally, the AppData\Roaming\Druva folder was never created, indicating the application failed to initialize for the user account.
Cause
The root cause was identified as a Windows DCOM (Distributed Component Object Model) permission error:
Application SID does not match Conductor SID.
This is a Windows-level security configuration conflict, not a Druva software bug. The mismatch in security identifiers (SIDs) prevented the Druva GUI from launching and blocked communication between services.
Traceback / Logs
Event Viewer Logs:
Error message:
Application SID does not match Conductor SID
Associated with CLSID and APPID entries in the DCOM configuration.
Behavioral Symptoms:
Druva client UI non-responsive.
No AppData\Roaming\Druva folder created.
Manual service restart did not resolve the issue.
Resolution
Identify Identifiers:
From the Event Viewer, note the CLSID and APPID associated with the error.
Update DCOM Configuration:
Run dcomcnfg.
Navigate to:
Component Services → Computers → My Computer → DCOM Config.Locate the application using the CLSID/APPID.
Adjust Security Permissions:
In the application properties, under Security, grant Local Launch and Local Activation permissions to the relevant user account or SYSTEM.
Verify Service Account:
Ensure the Druva inSync Client Service runs under the correct context and restart the service.
Clean Reinstall (if needed):
If permissions are fixed but the issue persists, perform a clean reinstall with elevated rights.
References: