Resolving PCS 7 V9.1 SP2 WinCC Runtime DLL System Errors

Resolving PCS 7 V9.1 SP2 WinCC Runtime DLL System Errors

Problem Overview

PCS 7 V9.1 SP2 WinCC Runtime installation on SIMATIC IPC647D or IPC847D stations fails with a Windows System Error dialog citing a missing dynamic-link library. The dialog text reads: The code execution cannot proceed because xxx was not found. Reinstalling the program may fix this problem. where xxx is one or more of the following modules:

• ACE60_x64.dll
• SCSDiscoveryX.dll
• CCCAGeneral.DLL
• CCAppHealthCheck.dll

The error occurs during the component-launch phase of the WinCC V7.5 SP2 Runtime installer that ships inside the PCS 7 V9.1 SP2 media. It has been reproduced on Microsoft Windows 10 IoT Enterprise 2019 LTSC (image part number 6ES7650-4MB00-1UA0) and on Windows Server 2019 when these operating systems are deployed through a partition-level image restore before the PCS 7 setup is executed.

The symptom is not a corrupt setup: the same media installs cleanly on a freshly partitioned system or when the WinCC Runtime portion is installed through the User-defined package path of the PCS 7 setup launcher. The DLLs themselves are present in the source distribution but the installer dependency-check chain cannot resolve them in the failing scenario.

Affected Versions and Environment

Refer to the official PCS 7 V9.1 SP2 PC Configuration manual for the full hardware and software matrix that must be satisfied before installation is attempted: PCS 7 - PC Configuration (V9.1 SP2).

Catalog of Missing DLLs

Each DLL belongs to a specific Windows-side dependency that the WinCC V7.5 SP2 Runtime installer links against at component launch. The installer reads the dependency graph from the manifest embedded in the runtime package; if the manifest cannot be parsed or the registered path does not match what the runtime setup expects, the loader fails before any WinCC service is registered.

When one of these DLLs is reported missing, the loader dialog halts the install. Continuing through the error does not register the WinCC services; the next reboot leaves the OS project unable to open in SIMATIC Manager and prevents the creation of OS objects in the engineering client.

Root Cause

The root cause is a stale or partial operating-system image that has been restored at the partition level rather than at the full-disk level. In the documented migration (PCS 7 V9.0 SP3 to V9.1 SP2 UC02 on IPC647D/IPC847D), the engineering team restored the Windows 10 IoT Enterprise 2019 LTSC 64-bit image (part number 6ES7650-4MB00-1UA0) using the SIMATIC IPC Image & Restore tool with the "Restore Windows partition only" option. The hidden recovery partition and the EFI System Partition were preserved from the prior V9.0 SP3 environment, while only the Windows volume was rewritten.

Two failure mechanisms follow:

1. The WinCC V7.5 SP2 Runtime installer reads the partition table and recovers installer state from the system volume. With a partial restore, the recovered state references ACE60_x64.dll, SCSDiscoveryX.dll, CCCAGeneral.DLL, and CCAppHealthCheck.dll at paths or with dependencies that no longer match the V9.1 SP2 distribution. The loader then reports the DLLs as missing.
2. The recovery-state fragment still binds the installer to the SQL Server 2017 instance configuration that PCS 7 V9.0 SP3 created. When the user-defined installation path is selected as a workaround, the SQL instance is skipped because the recovery state interprets the request as an upgrade rather than a fresh install. SIMATIC Manager then fails to open OS projects or create OS objects because the underlying SQL Server 2017 instance is not present.

The corrective procedure that eliminates both mechanisms is a full-disk reset of the IPC, followed by a clean PCS 7 V9.1 SP2 install.

Solution A — Full Partition Reset and Clean Install (Recommended)

Use this path when the station will be repurposed to PCS 7 V9.1 SP2 from any prior PCS 7 release, or when the OS image has been deployed through a partition-level restore.

Prerequisites

• SIMATIC IPC647D or IPC847D with BIOS boot order that lists the recovery / restore media first.
• USB recovery media built from part number 6ES7650-4MB00-1UA0 (Windows 10 IoT Enterprise 2019 LTSC 64-bit for SIMATIC IPC647D/IPC847D) or the equivalent DVD image for Windows Server 2019.
• PCS 7 V9.1 SP2 installation media. Prefer the extracted media (PCS_7_V9120.exe) downloaded through Automation License Manager Online Software Delivery.
• Administrator credentials for the IPC.
• Network access to the SIMATIC License Manager / Automation License Manager host.

Procedure

1. Boot the IPC from the recovery media.
2. In the SIMATIC Image & Restore tool, choose Reset partition and start everything from fresh. Do not choose "Restore Windows partition only".
3. Confirm that the recovery tool rewrites the EFI System Partition, the recovery partition, and the Windows partition. Wait for the tool to report a clean restore.
4. Allow the operating system to complete its first-boot configuration. Apply any OS-level updates, including .NET Framework servicing updates that the WinCC V7.5 SP2 Runtime installer will require.
5. Insert or mount the PCS 7 V9.1 SP2 media. If you are using the DVD image, open the DVD drive properties in Windows and enable Auto-mount before launching setup. The Auto-mount toggle is not enabled by default on Windows Server 2019 or Windows 10 IoT Enterprise 2019 LTSC; PowerISO is no longer required because Windows handles ISO mounting natively.
6. Launch the PCS 7 V9.1 SP2 setup from the root of the media or from the extraction folder. Accept the standard install path; do not choose a user-defined package at this stage.
7. When the setup reaches the package selection dialog, choose the full PCS 7 V9.1 SP2 package list that includes WinCC Runtime, SIMATIC Manager, PCS 7 OS components, and the SQL Server 2017 instance.
8. Complete the installation. The setup must finish without any DLL system-error dialog.
9. Install the relevant Update Collection (for example, UC02) if it is required by your plant baseline.
10. Reboot the station and validate that SIMATIC Manager opens the OS project and that OS objects can be created.

Solution B — User-defined Package Install (Caveated Workaround)

If a full partition reset is not possible, the WinCC Runtime portion of the install can be completed through the user-defined package path. This approach is a workaround only; it is not the recommended corrective action because of the SQL Server side effect described below.

Procedure

1. Launch the PCS 7 V9.1 SP2 setup. When prompted, choose User-defined package.
2. In the package tree, select WinCC Runtime only.
3. Complete the WinCC Runtime install. The DLL system-error dialog will appear; click through it and allow the installer to finish to the end of the package.
4. Restart the station.
5. Re-launch the PCS 7 V9.1 SP2 setup. Choose User-defined package again and select WinCC Runtime.
6. Complete the second pass. The DLL errors do not appear and the runtime services register correctly.
7. Install the Update Collection if your plant baseline requires it.

Caveat — SQL Server 2017

The user-defined path skips the SQL Server 2017 instance install. PCS 7 V9.1 SP2 expects a local SQL Server 2017 for the WinCC archive database and for the engineering database. If SQL is missing, the symptoms are:

• SIMATIC Manager opens the PC station but reports errors when opening OS projects.
• OS objects cannot be created in the engineering view.
• The WinCC Explorer cannot attach to a local SQL instance.

After Solution B completes, install Microsoft SQL Server 2017 manually, apply the SQL Server patches that ship on the PCS 7 V9.1 SP2 media, then re-run the PCS 7 setup to register the OS server / OS client components against the new instance.

DVD Image vs Extracted Media

The setup media format matters. Two delivery formats exist for PCS 7 V9.1 SP2:

If you cannot enable Auto-mount reliably on the target station, use the extracted media path. The extraction program decompresses the full distribution into a folder that the PCS 7 setup can read with no intermediate mount layer.

Recovery Partition Behavior on SIMATIC IPC

The SIMATIC IPC647D and IPC847D ship with a recovery partition that contains the SIMATIC Image & Restore tool and the factory Windows image. The recovery partition is signed and visible only to the SIMATIC restore environment. When the recovery tool runs in "Restore Windows partition only" mode, it preserves the recovery and EFI partitions but rewrites only the Windows volume. The boot configuration data (BCD) store on the EFI partition is then a composite of the prior OS and the new OS, which is the structural reason that the WinCC V7.5 SP2 Runtime installer dependency-check fails.

The corrective behavior is achieved by selecting "Reset partition and start everything from fresh". The recovery tool rewrites all three partitions and resets the BCD store to a known-good configuration. The first boot of the freshly reset system initializes the OS without inherited state from the previous install, and the PCS 7 V9.1 SP2 setup then resolves all DLL dependencies cleanly.

Verification

After applying Solution A or Solution B, run the following checks before declaring the install successful:

1. WinCC services registered. Open services.msc and confirm the WinCC services (CCAgent, WinCC Explorer, WinCC Runtime) are listed and set to Automatic startup.
2. SIMATIC Manager opens OS project. Launch SIMATIC Manager, open the OS project assigned to the station, and confirm that the OS compiles and downloads to the target without errors.
3. OS object creation. From SIMATIC Manager, attempt to create a new OS object (for example, a new picture or a new archive tag). Creation must succeed and persist.
4. SQL Server 2017 present. Open SQL Server Configuration Manager and confirm that the PCS 7 instance is running. Connect with SQL Server Management Studio and confirm the WinCC archive database is mounted.
5. DLL load check. Open regedit and search for the four DLL names under HKLM\SOFTWARE\Wow6432Node\SIEMENS\WinCC. Each must have a registered path that points to an existing file on disk.
6. Update Collection applied. Verify that the installed Update Collection level (for example UC02) is reported by SIMATIC Manager under Help > About.

Troubleshooting Matrix

Related Installation Notes

• The PCS 7 V9.1 SP2 setup must be run with administrative privileges. Right-click the setup launcher and choose "Run as administrator" even if the current user is in the local Administrators group.
• The MS server role (PCS 7 OS server with system diagnostics enabled) and the MS client role (engineering station) install different component sets. Confirm the role before selecting packages. See the PCS 7 PC Configuration manual for the component lists per role: PCS 7 PC Configuration V9.1 SP2.
• When migrating from V9.0 SP3 to V9.1 SP2, the OS image must be re-deployed through the full-disk reset path even if the underlying IPC hardware is unchanged. The BCD store and recovery partition signatures do not carry forward between major PCS 7 releases.
• If your plant uses centralized licensing, ensure the Automation License Manager service is reachable from the IPC at install time. WinCC Runtime will start without a local license but will not retain project state.
• Keep the Update Collection installer separate from the base PCS 7 V9.1 SP2 installer. Apply the Update Collection after the base install completes and the station has been rebooted at least once.

FAQ