Resolving Cancel Error Copying Project Data During PCS 7 OS Download

The error 'Cancel: Error copying the project data to the destination system' during an OS download in SIMATIC PCS 7 V8.1 typically occurs after manual uninstallation and reinstallation of Microsoft SQL Server from retail media. WinCC requires a highly specialized SQL Server instance (WINCC) configured with proprietary collation, service accounts, and database detachment handlers. If standard SQL Server is installed independently, the OS transfer routine fails to detach and unlock the project database files (.mdf and .ldf), causing the file-copying engine to timeout. To resolve this, run the official Siemens PCS 7 setup in Repair mode or restore a certified system backup image.

OS Download Architecture and the WinCC SQL Instance

In SIMATIC PCS 7, downloading an Operator Station (OS) from the Engineering Station (ES) across the plant terminal bus involves a coordinated sequence between SIMATIC Manager, the WinCC Project Duplicator, and Microsoft SQL Server. The process executes in distinct operational stages: project validation, temporary closure, server data generation, database detachment, network file transfer, remote database attachment, and automatic computer name adaptation.

Crucially, the WinCC database instance (.\WINCC) does not operate like standard enterprise SQL databases. It contains specialized Siemens extended stored procedures and background services that temporarily detach the project database (*RT.mdf) during network replication so that Windows file-copying services can transfer the binary database files without incurring sharing violations.

Root Causes: Manual SQL Reinstallation and File Locking

When engineers encounter WinCC database errors (such as 'Microsoft SQL Server cannot access the database'), a frequent fatal mistake is uninstalling and reinstalling Microsoft SQL Server 2008 R2 from commercial or Microsoft retail installation media. This breaks the system due to several factors:
- Missing Siemens Collation & Instance Parameters: The WinCC SQL instance requires exact binary collation (Latin1_General_BIN), specific mixed-mode authentication keys, and predefined local user groups (SQLServer2008R2WinCCOMSUser$...). Standard SQL setups omit these.
- Failed Database Detachment: During OS download, the ES command instructs the SQL Server to release file handles. Because the generic SQL instance lacks WinCC detachment hooks, the database files remain locked in exclusive use. After approximately six minutes of failed copy attempts, the OS loader terminates with Cancel: Error copying the project data.
- Administrative Share Permissions: The download targets administrative shares (e.g., \\Ossvrred\d$\PROJECT). If the Windows user lacks administrative privileges on the target server, Windows file copy aborts.

Diagnostic Matrix for OS Download Copy Failures

The table below details error phases, diagnostic log messages, and root causes during OS downloads:

Download PhaseLoad Log MessageRoot CauseCorrective ActionTarget CheckThe target directory can be read and written toVerified network SMB share permissions.Normal operation; share access confirmed.Project ClosureThe WinCC project is being closedSignals SQL Server to detach database handles.Normal operation; local handles closed.Network TransferCancel: Error copying the project dataDatabase files locked by SQL Server or SMB copy failure.Repair WinCC SQL instance; check administrative share rights.Lock ReleaseThe lock on the project was removedAutomated abort routine clearing temporary lock flags.Generated automatically following copy failure.Generic SQL SetupCannot access database, check rightsSQL Server installed from non-Siemens media.Reinstall WinCC from PCS 7 Toolset DVD.

Step-by-Step Recovery and System Restoration Procedure

Audit SQL Server Instance Configuration:
- Open SQL Server Configuration Manager: verify that instance WINCC exists and is running under NT AUTHORITY\SYSTEM.
- Check SQL Server collation in SQL Server Management Studio: confirm it is Latin1_General_BIN. If standard Latin1_General_CI_AS is shown, the instance is non-compliant and must be removed.
Execute Siemens WinCC Repair Installation:
- Insert the original SIMATIC PCS 7 V8.1 Toolset DVD 1.
- Run Setup.exe with administrative privileges.
- Select Package Installation -> choose Modify / Repair.
- Select Microsoft SQL Server 2008 R2 SP1 64-Bit (for WinCC) and SIMATIC WinCC.
- The Siemens installer configures the SQL Server instance with certified security descriptors and communication hooks.
Verify Network Sharing and Rights:
- On the target OS Server, verify that the project drive (e.g., drive D:) has administrative sharing (D$) enabled.
- Ensure the logged-on ES user exists on the target OS Server with an identical password and belongs to SIMATIC HMI and Administrators.
Reset WinCC Project State:
- On both ES and OS Server, execute CCResetProject.exe to flush orphaned database connections.
Execute OS Download:
- In SIMATIC Manager on the ES, right-click the OS object -> select PLC -> Download.
- Select Entire Project: monitor the download log; verify successful transfer and automatic remote project registration.

Verification

Verify OS download success through the following milestones:
1. Confirm that the OS load log completes with The WinCC project was transferred successfully.
2. Check the target OS Server project folder: verify that all *.mdf and *.ldf database files are intact and matching the ES date.
3. Launch WinCC Explorer on the target OS Server: confirm that the project opens without 'Cannot access database' errors and activates into Runtime cleanly.

Limitations and Operational Precautions

Never manually install, update, or patch Microsoft SQL Server using third-party or generic Microsoft update tools on a PCS 7 system. SQL Server updates for PCS 7 are delivered strictly via Siemens Update Collections (UC) or tested Siemens hotfixes. Applying untested Microsoft SQL cumulative updates can permanently corrupt the WinCC message and archive database structures. Always maintain verified full system disk image backups (e.g., Acronis True Image or SIMATIC Image & Partition Creator) before performing software maintenance.