Resolving WinCC Client AutoStartRT 'Server Not Available' Error

1. Problem Definition: WinCC AutoStartRT Server Not Available

On a SIMATIC WinCC v6.2 multi-user system, the client stations launch the WinCC runtime through the AutoStartRT entry configured in the WinCC project. After a period of reliable operation, the client logs in, attempts to start the runtime, and immediately receives a "Server Not Available" dialog. The runtime does not proceed past the login screen; it loops between the login prompt and the error dialog until the operator intervenes. The error appears on all four clients simultaneously, which indicates a centralized failure rather than an isolated client workstation fault.

This fault is distinct from a runtime crash, a project loading error, or a license violation. The error text is generated by the WinCC connection manager when the client process cannot establish a logical channel to the WinCC server during the auto-start sequence. The root cause can be in any of the following layers:

• Layer 1 – TCP/IP network reachability (IP, subnet mask, default gateway, DNS/WINS, NetBIOS).
• Layer 2 – Windows name resolution and remote procedure call (RPC) / DCOM permissions.
• Layer 3 – SIMATIC Shell configuration and Server Data assignment on the client.
• Layer 4 – WinCC services on the server (CCEsGrafRT, CCRtManager, CCDistributor, CCSysdiag).
• Layer 5 – User account control, login credentials, and group membership for the auto-start account.
• Layer 6 – Host firewall or third-party endpoint protection blocking the legacy WinCC ports (UDP 137/138, TCP 139, TCP 102, dynamic DCOM range).

The remainder of this article walks through each layer in sequence and provides verifiable checks at every step.

2. Affected Versions and System Topology

The reported environment is SIMATIC WinCC V6.2 SP3 running on a Windows Server 2003 / XP Professional client base. WinCC V6.2 is a legacy generation that predates TIA Portal but shares the same logical architecture: one WinCC Server holds the process image and archive database, and one or more WinCC Clients connect via the SIMATIC Shell transport (RPC over named pipes / TCP).

The same diagnostic flow applies to modern WinCC Runtime Professional (TIA Portal V20) installations. The conceptual steps—network reachability, project assignment, autostart configuration, service verification—are identical; only the menus and registry keys differ. For TIA Portal V20, refer to the official Additional settings: Autostart and language (RT Professional) documentation for the V20-specific autostart UI.

3. First-Line Diagnostic: Network Reachability

Before touching WinCC configuration, confirm the simplest layer: can the client resolve the server name and reach it on the required ports?

1. Open a command prompt on the affected client and run ping <ServerName> using the short computer name, the fully qualified name, and the IP address. All three must respond. If the short name fails but the IP works, the problem is name resolution (WINS, DNS, or NetBIOS).
2. Run ipconfig /all on both server and client. Verify that:
   • IP addresses are static (or DHCP reservations) and do not overlap.
   • The Subnet Mask is identical (e.g. 255.255.255.0).
   • The Default Gateway is present on every station if cross-subnet traffic is required.
   • Both stations register the same Primary DNS Suffix if they are in a domain.
3. Run nbtstat -a <ServerName> on the client. A registered <20> (File Server Service) entry must appear. If not, NetBIOS is broken—often because of a disabled TCP/IP NetBIOS Helper service or an overly aggressive firewall.
4. Open telnet <ServerName> 139 (or use PowerShell Test-NetConnection -Port 139) and confirm a session is established. Repeat for port 102 (S7ONLINE) if the server acts as a SIMATIC S7 gateway.

4. SIMATIC Shell and Server Data Verification

The SIMATIC Shell (the small SIMATIC icon in the system tray) is the runtime representation of the server/client relationship. On the client, right-click the SIMATIC Shell icon and select Settings:

1. Confirm the Server entry matches the computer name of the WinCC server (no trailing spaces, no FQDN when the project expects short name).
2. Click Test Connection. A successful test should return "Connection to server <Name> is OK" within 1–2 seconds.
3. If the test fails with Server Not Found, the WinCC Server service is not publishing its endpoint. Restart the CCEsGrafRT and CCDistributor services on the server.

The Server Data (German: Serverdaten) is the file generated in WinCC Explorer via Server Data > Create and copied to each client. It encodes the project path, the SQL instance, the redundancy configuration, and the user-rights list. If the server's IP, computer name, or SQL instance name changes after the Server Data was generated, the client holds stale information and will fail to connect.

1. On the server, open WinCC Explorer > Server Data.
2. Verify the path on the General tab; the default is <ProjectPath>\<ComputerName>\<ServerName>_ServerData.pck.
3. Regenerate the Server Data with Create even if no changes were made. This refreshes the file with current system information.
4. Copy the new *.pck file to C:\Program Files\Siemens\WinCC\ServerData on every client (or the path configured during the original install).
5. Open the client's SIMATIC Shell, point to the new Server Data file, and click Apply. The shell will prompt to log off and back on for the new rights to take effect.

5. AutoStartRT Configuration Walkthrough

On the client, the auto-start mechanism is implemented by a Windows shortcut or scheduled task that calls the WinCC client executable with the generated project package. In WinCC V6.2, this is typically:

"C:\Program Files\Siemens\WinCC\bin\AutoStartRT.exe" "C:\Program Files\Siemens\WinCC\ServerData\<ServerName>_ServerData.pck" /LANG=ENU

For modern systems running TIA Portal V20, the configuration is performed inside the TIA project and pushed to the runtime. The official Siemens documentation describes the procedure as follows (see Additional settings: Autostart and language (RT Professional)):

1. Open the WinCC RT Professional configuration in TIA Portal.
2. Navigate to the Autostart tab.
3. Activate Autostart.
4. In the Settings area, under Autostart project, select the WinCC server project to which the client should connect.
5. Compile and download the configuration to the client runtime.

For the legacy WinCC V6.2 path, verify the following on the client:

• The shortcut target exists and the file path is correct.
• The user account launching the shortcut has Modify rights to the ServerData folder.
• The shortcut is placed in the Startup folder of the auto-start user (%APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup) or invoked through AutoStart Configuration in WinCC Explorer.

If the auto-start user is a local account (not a domain account), and the server is a domain member, the Server Data lookup will silently fail. Always launch the WinCC client with the same account that has rights on the server's SIMATIC HMI user group.

6. Windows Services That Must Be Running on the Server

WinCC v6.2 relies on a tight set of services on the server. The Server Not Available message will appear if any of the following are stopped:

Run services.msc on the server and verify that every service in the table above is in the Running state. If the MSSQL$WINCC service has stopped, no WinCC client can establish a database session, and the auto-start logic will fail with the same symptom. Restart in this order: MSSQL$WINCC → CCEsGrafRT → CCDistributor → client workstation.

7. DCOM, Firewall, and User-Rights Configuration

WinCC uses DCOM (Distributed Component Object Model) heavily. A Windows security update or a GPO push can silently revoke DCOM rights and reproduce this exact error.

7.1 DCOM Access Permissions

1. On the server, run dcomcnfg.
2. Navigate to Component Services > Computers > My Computer.
3. Right-click My Computer > Properties > Default Properties tab.
4. Set Enable Distributed COM on this computer to checked.
5. On the COM Security tab, click Edit Limits under Access Permissions and ensure Everyone or the Authenticated Users group has Local Access and Remote Access.
6. Repeat under Launch and Activation Permissions.

7.2 Windows Firewall

The Windows Firewall on the server and on every client must allow the following inbound rules:

If the firewall was the cause, create inbound rules with scope limited to the IP range of the WinCC subnet to minimize exposure.

7.3 User Account Rights

On the server, the auto-start user (and every user expected to log in to the client) must be a member of:

• SIMATIC HMI
• SIMATIC HMI VIEWER
• SQLServerMSSQLUser$<ComputerName>$WINCC

Membership can be verified with net user <username> /domain from any command prompt. If the user was added to these groups after the server was rebooted the last time, the user must log out and back in on the client to receive a fresh Kerberos ticket.

8. Step-by-Step Diagnostic Procedure

Execute the following procedure in order. Stop at the first step that fails and remediate before moving on.

1. Verify network reachability. ping by IP, FQDN, and short name from a client. All three must succeed.
2. Verify name resolution. nbtstat -a <ServerName> shows registered services.
3. Verify port accessibility. Test-NetConnection -Port 445 and -Port 102 (if applicable) both return TcpTestSucceeded: True.
4. Verify WinCC services on the server. Every service in the table of Section 6 is Running.
5. Verify SQL Server. SQL Server Configuration Manager shows MSSQL$WINCC started. Open SQL Management Studio and connect to localhost\WINCC with the WinCC service account.
6. Regenerate and reapply Server Data. See Section 4.
7. Re-test SIMATIC Shell connection on the client. Right-click > Settings > Test Connection.
8. Launch the runtime manually. From the client, run AutoStartRT.exe with the Server Data path as argument. If it starts, the auto-start mechanism (Startup folder, scheduled task, or registry Run key) is the problem.
9. Launch the WinCC client from the server. From the server's own console, open SIMATIC Shell and add the local server. If the server cannot start its own runtime, the project itself is corrupted; restore from backup.
10. Capture diagnostics. Enable the WinCC diagnostics trace (CCSysDiag on the server) and review C:\Program Files\Siemens\WinCC\Diagnostics log files for the Connection and License channels.

9. Verification and Acceptance Test

After remediation, perform the following acceptance checks on every client:

1. Reboot the client while the server remains running.
2. Log in with the auto-start user. The WinCC runtime should appear within 30 seconds without any user interaction.
3. Confirm the process CCEsGrafRT.exe is visible in Task Manager on the client.
4. In the running runtime, open the System Information or Status dialog and confirm the Server field shows the correct computer name and a green connection indicator.
5. Force a value change in a tag on the server (or in the WinCC tag simulation) and confirm the change is reflected on the client within the configured update cycle (default 1 s).
6. Repeat steps 1–5 with the server cold-booted, to simulate a power outage scenario.

10. Common Pitfalls and Field-Notes

11. Quick Reference: WinCC Connection Ports and Services

# Sample verification script (run on a client)
Test-NetConnection -ComputerName <ServerName> -Port 445
Test-NetConnection -ComputerName <ServerName> -Port 139
Test-NetConnection -ComputerName <ServerName> -Port 135
Test-NetConnection -ComputerName <ServerName> -Port 102

# On the server
sc query CCEsGrafRT | findstr STATE
sc query CCDistributor | findstr STATE
sc query MSSQL$WINCC | findstr STATE

# Regenerate Server Data
"C:\Program Files\Siemens\WinCC\bin\CCProjectMgr.exe" /CreateServerData

12. When to Escalate to Siemens Support

If the procedure above does not restore connectivity, escalate with the following artifacts:

• Screenshots of SIMATIC Shell > Settings > Test Connection on a failing client.
• The full CCSysDiag log archive from the server for the timeframe of the failure.
• The WinCC.<ServerName>_<Timestamp>.log from C:\Program Files\Siemens\WinCC\Diagnostics\Logs.
• The output of systeminfo /s <ServerName> from the client.
• The exact build numbers: WinCC V6.2 SPx, Windows version, SQL Server version.

Open a support request at the Siemens Industry Online Support portal with the tag WinCC V6.2 Multi-User AutoStartRT Server Not Available. Provide the diagnostic package as a ZIP archive; large files may be uploaded through the secure Siemens SmartTrace link.