Troubleshooting PCS 7 V8.1 OS Server Download Error After SQL

Problem Overview

Engineers running SIMATIC PCS 7 V8.1 with WinCC Runtime on a paired OS Server / OS Standby architecture occasionally encounter a hard failure during the project download step. The symptom appears as the load log terminating at:

Cancel: Error copying the project data to the destination system.

The full load log sequence is typically:

1. The project was locked.
2. The entire WinCC project will be transferred to the runtime OS.
3. The path of the Runtime OS is indicated for the redundant partner.
4. The target directory can be read and written to.
5. No project is open.
6. The project was opened successfully.
7. The Picture Tree was updated.
8. Server data were created successfully.
9. The WinCC project is being closed.
10. Cancel: Error copying the project data to the destination system.
11. The lock on the project was removed.

Notice the failure occurs after server data generation succeeds. This isolates the failure to the file copy phase rather than the compile phase, narrowing the field of investigation to filesystem, network, or account-permission layers, not the SQL database itself.

Affected Components and Versions

Per the Siemens PCS 7 V8.1 Readme, the approved SQL Server revision is Microsoft SQL Server 2008 R2 SP2 (64-bit). Any deviation from this revision - including a fresh install that omits the SP2 slipstream - is a documented mismatch source.

Root Cause Analysis

The "Error copying the project data to the destination system" message is generated by the WinCC Project Duplicator / OS Project Editor when the SMB/CIFS write operation to the OS Server target path fails mid-stream. Because the log shows the source path is read successfully and the target directory is writable, the failure is almost always one of the following:

1. SQL service account mismatch after SQL reinstall. When SQL Server is reinstalled, the local service account (typically NT SERVICE\MSSQLSERVER or NT AUTHORITY\SYSTEM) is regenerated. WinCC creates a per-project SQL login that references the SQL service SID; if that SID changes, the WinCCProject.mdf/.ldf files become orphaned even though they appear intact in the file system.
2. WinCC user administration corruption. PCS 7 maintains a User Administrator database (CCUser) inside the SQL instance. After a SQL reinstall without restoring master.mdf, the WinCC administrator login is lost, but WinCC Explorer may still open because it caches the configuration locally. The OS download is the first operation that triggers a fresh auth handshake with the SQL instance, exposing the broken login.
3. Target folder ACL drift on the OS Server. Re-creating a folder with the same name does not always reproduce the original ACL because Windows inherits permissions from the parent when "Inherit from parent" is selected. Hidden SYSTEM or CREATOR OWNER ACE entries from the prior folder are missing on the new folder.
4. Antivirus / Windows Defender real-time scan. Real-time AV holds an exclusive lock on *.mcp, *.ldf, or *.pdl files mid-write, causing the SMB copy to fail after partial transfer.
5. SMB signing or SMB1 negotiation failure. Mixed OS server generations (e.g., Windows Server 2008 R2 OS Server plus newer ES) default to SMB2/SMB3 with signing required; if the OS Server has SMB1 enabled only, the file copy aborts silently.
6. Computer-name / path mismatches after SQL reinstall. Because the ES was repaired, the local computer name binding inside the WinCC project database may now point to a SID or hostname that the regenerated SQL instance cannot resolve.

Diagnostic Workflow

Follow this sequence before touching the OS Server. Each step ends with a pass/fail gate; do not proceed if a step fails.

Step 1 - Confirm the Load Log Termination Point

On the ES, right-click the OS in WinCC Explorer and choose OS Project Editor > Display Load Log. Record the timestamp of the last successful step and the first failure. The patterns map as follows:

Step 2 - Verify Network Path Reachability

From the ES, open an elevated command prompt:

net use \\Ossvrred\d$ /user:<domain\user> <password>
dir \\Ossvrred\d$\PROJECT\OSSVR

If net use returns System error 5 (Access is denied), the download will always fail. The user context of the WinCC download service must be the same Windows account that owns the share write permission.

Step 3 - Verify WinCC SQL Login Integrity

On the ES, open SQL Server Management Studio and connect to the local instance. Run:

SELECT name, type_desc, is_disabled FROM sys.server_principals
WHERE name LIKE '%WinCC%' OR name LIKE '%CCUser%' OR name LIKE '%SIMATIC%';

Expected output: at least one Windows-group or local-SQL login mapped to the WinCC project. If the result is empty, the SQL reinstall did not re-bind the WinCC login.

Remediation A - Re-bind the WinCC Login

1. Open WinCC Explorer on the ES.
2. Open the affected project.
3. Right-click User Administrator > Configure.
4. Add the local SIMATIC HMI Windows group with full rights.
5. Close and reopen the project.
6. Re-attempt the OS download.

Step 4 - Validate the WinCC Database Attach State

Locate the project database directory (typically D:\PROJECT\Working\<Plant>\<Plant_OS>\wincproj\<OS>\winccom\). Confirm the following files exist and are not zero bytes:

• <ProjectName>.mdf
• <ProjectName>_log.ldf
• CCAlgLog_<Project>.mdf
• CCAlgLog_<Project>_log.ldf

Run the following SQL query against the local instance:

USE master;
GO
SELECT name, state_desc, recovery_model_desc
FROM sys.databases
WHERE name LIKE '%PPL%' OR name LIKE '%WinCC%';
GO

If the project database shows state_desc = RECOVERING or SUSPECT, detach and re-attach with the following sequence:

USE master;
GO
EXEC sp_detach_db @dbname = 'PPL_OS';
GO
CREATE DATABASE PPL_OS ON
(FILENAME = 'D:\PROJECT\Working\PPL\PPL_OS\wincproj\OSSVR\winccom\PPL_OS.mdf'),
(FILENAME = 'D:\PROJECT\Working\PPL\PPL_OS\wincproj\OSSVR\winccom\PPL_OS_log.ldf')
FOR ATTACH;
GO

Restoring the SQL Server Layer Correctly

Because the original incident stemmed from a manual SQL uninstall/reinstall, the canonical Siemens procedure for SQL recovery in PCS 7 V8.1 must be followed precisely. The approved path is:

1. Insert the PCS 7 V8.1 installation DVD.
2. Run Setup as Administrator.
3. Select Modify Installation (not Remove/Install).
4. Navigate to SQL Server 2008 R2 and choose Repair.
5. Reboot when prompted.
6. Reapply PCS 7 V8.1 Update corresponding to the installed Service Pack (e.g., PCS 7 V8.1 SP1 or PCS 7 V8.1 SP2).
7. Reapply any installed Hotfix packages.

The Repair path preserves the original SQL service SID, master database ownership, and WinCC logins. A full uninstall + reinstall, by contrast, regenerates the SID and orphans the existing WinCC database principals.

OS Server-Side Hardening

Recreate the Target Folder with Explicit ACLs

On the OS Server (single OS or Master in redundant pair):

1. Delete the broken target folder (archive contents first).
2. Recreate the folder exactly as named in the ES download target, e.g., D:\PROJECT\OSSVR\.
3. Right-click > Properties > Security > Advanced.
4. Disable inheritance > Convert inherited permissions to explicit.
5. Add the following ACEs explicitly:

Disable Real-Time AV on the Project Path

Add the following paths to the AV exclusion list on both the ES and the OS Server:

• D:\PROJECT\**\*.mcp
• D:\PROJECT\**\*.mdf
• D:\PROJECT\**\*.ldf
• D:\PROJECT\**\*.pdl
• D:\PROJECT\**\*.PDL
• C:\Program Files (x86)\Siemens\Automation\WinCC\**
• C:\Program Files\Siemens\Automation\WinCC\**

Real-time scanning during the bulk file copy is the single most common silent abort cause on customer hardware such as the Dell PowerEdge R320 referenced in the incident.

Configure SMB Settings

On the OS Server, open PowerShell as Administrator and run:

Set-SmbServerConfiguration -EnableSMB1Protocol $false -Force
Set-SmbServerConfiguration -RequireSecuritySignature $true -Force
Set-SmbServerConfiguration -EnableSecuritySignature $true -Force

On the ES, ensure the same SMB2/SMB3 dialect is negotiated by checking Get-SmbConnection. Mismatched signing requirements manifest as mid-copy aborts that look identical to the reported load-log error.

Download Procedure (Step-by-Step)

Once the SQL and filesystem layers are restored, perform the download in the canonical sequence. The redundant OS Standby download follows the same procedure with the Standby server as target.

1. On the ES, open WinCC Explorer and load the master project.
2. Right-click the OS server object and select OS Project Editor.
3. Choose Compile / Check Consistency; resolve all warnings and errors before continuing.
4. Right-click the OS > Download to Target System.
5. In the download dialog, confirm the target computer name (e.g., Ossvrred) matches the actual OS Server hostname.
6. Confirm the target path (e.g., \\Ossvrred\d$\PROJECT\OSSVR) is reachable in Windows Explorer.
7. Select the redundancy mode: Standalone, Master, or Standby. The customer's plant was configured as Standby; ensure Master is downloaded first, then Standby.
8. Initiate the download. Monitor the load log in real time.
9. When the log reaches "The WinCC project is being closed", the file copy is in progress.
10. Verify the final line shows The lock on the project was removed. with no Cancel: entries.

Verification

After the download completes without error, perform the following verification gate before resuming production.

Checklist for OS Server Hardware (Non-Siemens IPC)

The Dell PowerEdge R320 referenced in the incident is non-Siemens IPC. Siemens explicitly cautions that hardware outside the SIMATIC PCS 7 catalog has not been validated. For non-certified hardware, follow the checklist:

1. Confirm BIOS is set to AHCI mode (not RAID-on-Motherboard for non-RAID O/S disks).
2. Disable C-State and SpeedStep in BIOS to ensure deterministic runtime behavior.
3. Install the vendor NIC driver (Broadcom / Intel) directly; do not use Windows inbox drivers.
4. Disable Energy Efficient Ethernet on the management NIC.
5. Apply Windows Server recommended hotfixes for SMB2/SMB3 stability.
6. Back up the OS partition image with Acronis / Veeam before commissioning.

Preventive Measures

• Never manually uninstall SQL Server on a PCS 7 workstation. Always use the PCS 7 Setup > Modify > Repair path. The PCS 7 installer maintains the SQL service SID, registry references, and WinCC login mappings.
• Maintain periodic image backups. Use Acronis True Image / Veeam Image Backup on every PCS 7 station. The recommended cadence is a full image before each OS download attempt and a differential after each successful commissioning change.
• Backup the WinCC project database before download. Copy the project directory to a network share before initiating download. The Archive command in WinCC Explorer produces a single .zip that includes all *.mcp, *.mdf, and configuration files.
• License the OS Server stations. PCS 7 V8.1 licenses are tied to the Microsoft Software Licensing Service on each station. License backup via Automation License Manager should be performed before any SQL operation.
• Establish a controlled domain. Customer plants where the IT domain is managed by a third party without PCS 7 experience encounter chronic authentication issues. PCS 7 is officially supported only when the engineering and runtime stations belong to a domain where the IT administrator understands the WinCC service accounts.
• Restrict Windows Update. Configure a controlled WSUS server so SQL Server 2008 R2 does not receive a feature update that breaks the SQL-WinCC link. Only critical security updates should be approved.

Troubleshooting Matrix

FAQ