Resolving WinCC flexible ES/RT Version Mismatch on IPC277D

1. Problem Overview

Engineers commissioning a SIMATIC IPC277D Nanopanel PC with WinCC flexible Runtime (PC-RT) frequently encounter a hard-stop during project transfer: the Engineering Station (ES) builds the project without warnings, the runtime loader on the panel accepts the transfer request, and the download is interrupted with the message:

14:04:29.54 Transfer   Info  : Download is not possible. This WinCC flexible ES version and the WinCC flexible Runtime software version on the operating unit are not compatible.
14:04:29.54 Transfer   Info  : Transfer failed!

The same symptom occurs when the panel is targeted as SIMATIC HMI Panel rather than Panel PC in the device configuration. This article documents the exact root cause, the matching service-pack policy enforced by Siemens, the license implications, and a step-by-step recovery procedure. The matching problem class also surfaces in current TIA Portal / WinCC Unified workflows as described in the Siemens documentation: Error messages during loading of projects (RT Unified).

2. Affected Hardware and Software Stack

3. Transfer Log Dissection

The transfer log captured during the failed attempt is short but unambiguous. Each line is reproduced below together with the engineering meaning and the expected condition for a successful transfer.

The 1.5 s gap between Establishing connection to device and the version-mismatch error is the network handshake completing successfully; the runtime then inspects the project header and rejects it on SP version. This rules out cabling, IP addressing, and firewall as the failure cause.

4. Root Cause

WinCC flexible 2008 enforces a strict ES = RT version parity rule. The transfer carries a project header that includes the ES build, the SP number, and the hotfix/update identifier. The runtime validates this header against its own internal version record before accepting a single byte of runtime data. If any of the following differ, the transfer is rejected with the message above:

• Major version (2008 vs. 2005 vs. 2007)
• Service Pack level (SP1 vs. SP2 vs. SP3 vs. SP4 vs. SP5)
• Update / Hotfix identifier (e.g., Update 1, Update 2, HF7)

In the affected unit, the ES was updated to SP3 (typically delivered through the WinCC flexible 2008 SP3 Update media), while the IPC277D still carried the original SP2 RT image that was bundled with the license. Because SP2 RT does not know how to interpret a project compiled by SP3 ES, the loader aborts the transfer.

A secondary but important observation: the ES is not blocked from selecting Panel PC in the device tree for an IPC277D, but the resulting project will be tagged as PC-RT and not Panel RT. The runtime build needed on the target is therefore WinCC flexible 2008 Runtime (PC-RT), not the embedded Panel RT used for the OP/TP/MP product lines. The recipe-license message in the log confirms the runtime build targeted.

5. License Requirements

Three license classes are relevant for an IPC277D running WinCC flexible PC-RT:

The log line Required license: WinCC flexible /Recipes for PC-RT is emitted by the compiler and is informational; it does not gate the transfer. The runtime, however, will refuse to start visualization with recipes if the corresponding license is not present. Always install Recipes for PC-RT on the IPC277D when the project contains one or more recipe views.

6. Prerequisites for Recovery

1. Inventory of installed media. Locate the WinCC flexible 2008 SP3 Update DVD (or downloaded package) and the matching SP3 Update install for the PC-RT. Verify the printed part number matches the Engineering Station installation.
2. Administrative credentials on both the engineering PC and the IPC277D (XPe is configured with the Siemens user, password Siemens by default — change before connecting to a live network).
3. Ethernet connectivity between ES and IPC277D, same subnet, ping test green from both directions.
4. Loader setting Enable Transfer ticked, Remote Control allowed, and (for XPe) the Enhanced Write Filter (EWF) configured to commit changes after install.
5. Snapshot / image of the IPC277D before any update. Use SIMATIC IPC Image & Partition Creator or a third-party tool such as Acronis True Image.

7. Step-by-Step Recovery Procedure

1. Confirm the ES version. On the engineering PC, open WinCC flexible 2008 ES, then Help → About. Record the full version string, e.g. WinCC flexible 2008 SP3 Update 1 (1.4.0.0_1.50). The build must end with a hotfix identifier.
2. Confirm the RT version on the panel. On the IPC277D, start WinCC flexible Loader, then Help → About or inspect C:\Program Files\Siemens\Automation\WinCC flexible 2008 RT\Readme.rtf. Record the SP and hotfix level. If the panel is at SP2, an update is mandatory.
3. Open a Siemens support request for the SP3 Update media if it is not on hand. The ES-2008 SP3 Update and the RT-2008 SP3 Update are distributed as separate packages and the RT update is not always included in the box-delivered license media.
4. Apply the SP3 Update on the ES. Run Setup.exe from the ES SP3 Update package, accept the license, and reboot. Re-verify the version string in Help → About.
5. Disable the EWF on the IPC277D before installing the RT update: open an elevated command prompt and run ewfmgr c: -commitanddisable followed by a reboot. With the EWF disabled, file changes persist across restarts.
6. Install the RT SP3 Update on the IPC277D. Copy the package to C:\Temp\WinCC_RT_SP3 and run Setup.exe. Reboot when prompted.
7. Re-enable the EWF (recommended for production) with ewfmgr c: -enable and capture a clean image with the partition tool.
8. Start the WinCC flexible Loader on the IPC277D and select Transfer. The transfer button must be enabled and Remote mode set.
9. Trigger a transfer from the ES: Project → Transfer → Transfer. The transfer window should now show Download is being prepared, then Transferring Device_1, then Transfer finished! in roughly 20-40 s for a 285 kB project.
10. Verify the runtime. Once transferred, the runtime should start automatically (if the loader is set to Start Runtime), display the start screen, and respond to the first operator input within 2 s.

8. Verification Checklist

9. Troubleshooting Matrix

10. Preventive Measures

• Maintain a single, version-controlled repository for the WinCC flexible installation media. Tag every DVD / ISO with SP + Update + build number.
• Capture a full disk image of the IPC277D immediately after commissioning. This image is the gold standard for any future RMA or factory reset.
• Document the ES and RT version strings in the project header. WinCC flexible stores these in the project properties and the runtime stores them in System\Version; diffing the two before a transfer is a 30 s check that prevents a 30 min fault.
• Disable Windows Auto-Update on the IPC277D. Service packs and hotfixes from public Microsoft channels can move the underlying OS build and trigger further compatibility drift with the WinCC RT image.
• When commissioning multiple IPC277D units, apply the update on a single reference unit, verify, image, and clone — this avoids divergent patch levels on the shop floor.

11. Reference: Common Version Strings

12. FAQ