Resolving OS Download Error 310 -88 and Locked WNF File Transfers in PCS 7

In SIMATIC PCS 7, encountering error "(310:88) Error occurred during download to target system" while copying navigation or SFC framework files (such as SfcStartPackageBrowser.wnf) during an OS project download to an OS Client or OS Server indicates an operating system access denial or active file lock on the target machine. This failure occurs when Windows user authentication credentials differ between the Engineering Station (ES) and the destination station, when network file sharing permissions on the target directory are revoked, or when orphan WinCC background processes (pdlrt.exe, CCApp.exe, s7tgtopx.exe) hold open file locks. Resolving this issue requires harmonizing Windows user accounts, terminating locked processes via reset_wincc.vbs, and verifying Windows SMB file share permissions.

Mechanism of OS Project Download and File Transfer

When an engineer downloads an Operator Station project from the Engineering Station (ES) to an OS Server or OS Client (PLC -> Download -> Selected Stations or Right-click OS -> PLC -> Download), SIMATIC Manager executes a multi-stage transaction:

Remote Target Handshake: Connects to the destination station via DCOM and Simatic Shell.
Database Duplication and File Synchronization: Copies the complete WinCC project directory structure, Microsoft SQL Server database files (.mdf/.ldf), screen graphics (.pdl), C/VBS scripts, and navigation configuration files (such as SfcStartPackageBrowser.wnf) over Windows Server Message Block (SMB on TCP port 445).
Target Registration: Registers the project in the target station's local WinCC project management repository.

If any single file within the project directory is locked by a running process or if the remote operating system rejects file write permissions, the file transfer aborts, producing the generic error: (310:88) Error occurred during download to target system.

Root Causes of Error 310:88 at SfcStartPackageBrowser.wnf

Halting specifically on SfcStartPackageBrowser.wnf highlights distinct operational triggers:

Failure MechanismTechnical Root CauseDiagnostic ObservationResolution ProcedureUser Account Password MismatchTarget OS account password modified; out of sync with ESWindows Event Log reports SMB / NTLM Logon Failure 4625Synchronize Windows username and password across ES and OSLocked File HandlesWinCC Runtime was not deactivated cleanly prior to downloadProcess pdlrt.exe or CCApp.exe active in Task ManagerExecute reset_wincc.vbs on the target stationShared Folder Permission LossTarget shared folder rights altered or removedFile copy transfers initial files then aborts on first subfolderGrant Full Control to SIMATIC HMI group on target shareFirewall Blockage on SMBTCP port 445 filtered or blocked by perimeter firewallConnection timeout during large file chunk transferOpen TCP 445 and dynamic RPC ports on Terminal Bus

In many plant environments, an IT security policy or administrative user modifies the Windows password on the OS Client without updating the corresponding credentials on the Engineering Station. When the ES attempts to write project files into the remote shared directory, Windows authentication fails mid-transfer.

Harmonizing Windows User Accounts and SIMATIC HMI Groups

In a SIMATIC PCS 7 workgroup environment, network file operations require identical security principals:

Identical Credentials: The active user logged into the Engineering Station must exist on the destination OS Client with the exact same username and password.
Group Memberships: On both the ES and OS Client, verify that the user account belongs to:
- Administrators (or standard engineering permissions).
- SIMATIC HMI (Mandatory for WinCC file access).
- SIMATIC NET (Mandatory for communications).
Verify Target Folder Sharing:
- On the OS Client, navigate to the target project directory.
- Right-click the project folder -> Properties -> Sharing -> Advanced Sharing.
- Confirm that the folder is shared with Permissions -> Full Control granted to the SIMATIC HMI group.

Terminating Orphan Processes Using reset_wincc.vbs

If user credentials are verified but file copying aborts due to locked file handles:

On the destination OS Client, close WinCC Explorer.
Open Windows Command Prompt or Windows Run dialog (Win + R).
Execute the standard Siemens WinCC process reset script:
cmd reset_wincc.vbs
This utility forces the graceful termination of all lingering WinCC runtime daemons, including pdlrt.exe, CCApp.exe, s7tgtopx.exe, and Split Screen Manager services.
In Windows Task Manager, verify that no WinCC* or CC* processes remain active.
Return to the Engineering Station and re-initiate the OS download.

Verification

To verify that the OS download can proceed without errors:
1. From the Engineering Station, open Windows Explorer and navigate to the UNC network share of the OS Client (e.g., \\OS_CLIENT_01\Target_Share\).
2. Create and delete a test text file inside the folder; confirm read, write, and delete permissions.
3. In SIMATIC Manager, initiate PLC -> Download -> Entire OS.
4. Confirm that the file transfer progress bar advances smoothly past SfcStartPackageBrowser.wnf and completes with status: Download finished successfully.
5. On the OS Client, open WinCC Explorer; confirm that the downloaded project opens cleanly.

Limitations and Operational Precautions

Never execute reset_wincc.vbs on an operational OS Server during live plant operations, as doing so immediately terminates WinCC Runtime and drops communication with the automation controllers. Only execute reset_wincc.vbs on dedicated offline clients or during planned maintenance outages. If a download repeatedly fails midway, move the existing client project directory to an archive folder and download a clean, entire project.

Engineer FAQ

What file is SfcStartPackageBrowser.wnf?

SfcStartPackageBrowser.wnf is an internal WinCC XML/binary configuration file used by the SIMATIC SFC Visualization package to index and browse compiled SFC charts and step types.

Can I download an OS project while WinCC Runtime is active on the target station?

On an OS Server in a redundant pair, you can download 'Changes only' while Runtime is active. On an OS Client, Runtime must generally be closed prior to performing an 'Entire OS' download.

Why must user passwords match in a workgroup?

In a Windows workgroup without an Active Directory Domain Controller, Windows uses pass-through NTLM authentication. If passwords differ, remote write access to shared folders is rejected.