Resolving 'Initialization Failed' on SIMATIC WinCC Explorer Launch in PCS 7 V8.1

The error 'Initialization failed' upon opening SIMATIC WinCC Explorer in PCS 7 V8.1 typically indicates an incompatible Microsoft Windows security patch (such as Meltdown/Spectre updates KB4056897 or KB4056894), a stopped Microsoft SQL Server instance (MSSQL$WINCC), missing Windows user group assignments, or a broken AS/OS Engineering component installation. To resolve the issue, install the latest Siemens PCS 7 V8.1 SP1 update (Upd9 or higher) or WinCC V7.3 Upd14 to restore DCOM/RPC compatibility, verify that the 'MSSQL$WINCC' Windows service is started, and ensure the active user belongs to the 'SIMATIC HMI' and 'SQLServerMSSQLUser$$WINCC' local groups.

WinCC Explorer Initialization Architecture

When SIMATIC WinCC Explorer (WinCCExplorer.exe) launches, it initializes several core runtime subsystems before displaying the project tree:

Component Object Model (COM) Registration: Binds to internal WinCC COM servers (CCProjectMgr.exe, CCClient.dll).
Microsoft SQL Server Connection: Connects to the local database instance MSSQL$WINCC using Windows authentication.
STEP 7 Integration Layer: In a PCS 7 engineering environment, queries the AS/OS Engineering COM interfaces to determine multiproject association.

If any of these subsystems fail to respond within the startup timeout window, WinCC Explorer aborts with the modal dialog Initialization failed.

Impact of Microsoft Windows Security Patches (Meltdown/Spectre)

In early 2018, Microsoft issued urgent operating system security patches addressing speculative execution vulnerabilities (Meltdown and Spectre, such as KB4056897, KB4056894, and cumulative rollups for Windows 7 / Server 2008 R2). These updates introduced strict kernel memory isolation and altered internal DCOM/RPC security boundaries.

In unpatched releases of WinCC V7.2 and V7.3 (PCS 7 V8.1), these Windows updates blocked the internal RPC communication between WinCCExplorer.exe and the WinCC database management service, triggering immediate Initialization failed errors. Siemens resolved this across SIMATIC PCS 7 by issuing dedicated compatibility updates (PCS 7 V8.1 SP1 Upd9 and WinCC V7.3 Upd14).

Microsoft SQL Server Instance Verification

WinCC cannot initialize if its underlying database engine is inaccessible:

Open Windows Services (services.msc) and locate the service named SQL Server (WINCC) (MSSQL$WINCC).
Verify that the service status is Running and Startup type is Automatic.
If the service is stopped or crashes upon startup, inspect the SQL Server error logs located at C:\Program Files\Microsoft SQL Server\MSSQL11.WINCC\MSSQL\Log\ERRORLOG.

Windows User Group Permissions and DCOM Hardening

WinCC requires strict membership in local Windows security groups created during installation:

Open Computer Management (compmgmt.msc) and navigate to Local Users and Groups > Groups.
Confirm that the currently logged-on user account is an explicit member of:
1. SIMATIC HMI
2. SIMATIC NET
3. SQLServerMSSQLUser$<ComputerName>$WINCC
If the user account was recently added or modified, a complete Windows sign-out or computer restart is mandatory to re-issue the Windows security access token.

Step-by-Step Diagnostic and Remediation Workflow

Follow this sequential troubleshooting procedure:

Check Windows Installed Updates:
- In Control Panel > Programs and Features > View installed updates, check for recently installed security KBs.
Apply Siemens Compatibility Updates:
- Install the latest Cumulative Update for PCS 7 V8.1 (SIOS Entry ID 18752994 / 109756832).
Reset WinCC Communication Cache:
- Open a command prompt as Administrator and execute CCResetCC.vbs from the WinCC bin folder (C:\Program Files (x86)\Siemens\WinCC\bin).
Re-register Core COM DLLs:
- Run the Siemens tool Register-DLL.bat or reinstall the AS/OS Engineering setup package from the PCS 7 installation media.

Troubleshooting Matrix for WinCC Explorer Startup Failures

The table below correlates root causes with diagnostic indicators and remedies:

Potential Failure CauseDiagnostic IndicatorVerification MethodCorrective RemedyMeltdown/Spectre Patch ConflictInitialization failed immediatelyCheck installed KBs against SIOS 18752994Install PCS 7 V8.1 SP1 Upd9 / WinCC V7.3 Upd14SQL Server (WINCC) StoppedService not running in services.mscInspect SQL ERRORLOG fileStart service; repair SQL instance if corruptedMissing SIMATIC HMI GroupAccess Denied in DCOM logInspect compmgmt.msc Local GroupsAdd user account to SIMATIC HMI group and rebootCorrupted Project Cache (.dcf)WinCC fails on specific projectDelete .dcf and re-openFile regenerates automatically from SQL databaseIncomplete AS/OS EngineeringMissing STEP 7 menu hooksCheck Installed Software in SIMATIC ManagerReinstall AS-OS Engineering from PCS 7 Disk 1

Verification

Confirm successful resolution of WinCC Explorer startup:

Click the Windows Start menu and launch SIMATIC WinCC Explorer.
Confirm that WinCC Explorer launches to its primary interface without displaying initialization errors.
Open a sample or plant project; confirm that the Graphics Designer, Tag Management, and Alarm Logging editors load.
Open SIMATIC Manager and verify that right-clicking an OS station and selecting Open Object launches WinCC Explorer seamlessly.

Limitations and Operational Precautions

Adhere to the following engineering precautions:

Validate Windows Updates Prior to Deployment: Never enable automatic Windows Updates on production PCS 7 servers. Always verify update compatibility against the official Siemens Compatibility Tool before installing patches.
Do Not Modify SQL Server Configuration: Do not alter SQL Server instance settings, database names, or collation settings directly via SQL Server Management Studio (SSMS), as this will permanently invalidate WinCC integration.
Backup Projects Before Resetting: Always create a complete archive of the PCS 7 multiproject before running cleanup scripts or re-installing AS/OS components.

Engineer FAQ

Can I fix 'Initialization failed' by uninstalling the latest Windows update?

While temporarily rolling back the problematic Windows update will allow WinCC to launch, it leaves the system vulnerable to security exploits. The officially recommended solution is installing the Siemens update (e.g. WinCC V7.3 Upd14) which supports the security patch.

Why must the Windows user be in both SIMATIC HMI and SQL Server user groups?

The SIMATIC HMI group grants access to WinCC COM/DCOM interfaces and shared memory. The SQLServerMSSQLUser group grants database authentication rights to the local WinCC Microsoft SQL Server instance.

What does the CCResetCC.vbs script do?

CCResetCC.vbs terminates all lingering background WinCC processes (such as CCProjectMgr, CCHmiData, and CCClick) and cleans up orphaned shared memory handles, allowing WinCC to initialize cleanly.