Resolving WinCC Unified V17 System Alarm Placeholder Text

Problem Overview

WinCC Unified Runtime (RT) running on a TIA Portal V17 engineering base can render system alarms with raw placeholder tokens (for example @ConfigErrorAlarmTextLibrary::... or unresolved %... macros) instead of localized text. The defect is most often seen after a TIA Portal update is installed against a project that originally targeted an earlier runtime image. Operators see unreadable characters in the Alarm control, and the alarm log records a Connection failed condition that never produces a human-readable message.

The fault is not a localization defect: switching the runtime language from Italian to English (or back) does not change the placeholder output. It is a configuration reference (CRef) resolution failure caused by an image version mismatch between the engineering project and the installed runtime. Correcting the image version of the HMI device to match the TIA Portal Update level restores text resolution.

Symptoms and Error Description

The failure manifests in three observable layers simultaneously:

1. Alarm control: The Message text column of the Alarm control shows unresolved placeholder strings instead of the expected localized sentence.
2. Alarm log: System alarms with the Connection failed cause are written, but the text portion is empty or contains @TextID:#### tokens.
3. TraceView: The runtime trace viewer reports the diagnostic message The CRef for textlist "ConfigErrorAlarmTextLibrary" cannot be resolved. The message appears once per OPC UA client connection that fails.

Reported environment:

• Engineering: TIA Portal V17 Update 5
• Runtime host: Windows Server 2016 Standard, Build 14393.6297 (LTSC)
• Runtime languages configured: Italian (default) and English (fallback)
• OPC UA clients configured: 2 (separate connections)
• Affected alarm class: Connection diagnostics (system alarms 1xxxx range)

Environment and Version Matrix

TIA Portal V17 distributed updates ship new WinCC Unified runtime images. A project compiled against an earlier Update retains the original image version unless explicitly upgraded. The table below summarizes the V17 service levels relevant to this defect.

Engineering installations of TIA Portal V17 Update 5 install runtime images up to and including V17.0.0.5 on the engineering PC and the HMI target. Projects created against earlier Updates (V17.0, V17 Update 1, etc.) retain the older image version reference until manually upgraded.

Root Cause: Runtime Image Version Mismatch

WinCC Unified system alarms source their visible text from a built-in text list named ConfigErrorAlarmTextLibrary. The library is versioned together with the runtime image. When the project refers to a runtime version that is older than what the HMI target ships with, two symptoms appear:

1. The compiled alarm bitmaps and CRef pointers are bound to the older library version.
2. The runtime attempts to dereference a CRef that no longer exists in the installed image, producing the trace error The CRef for textlist "ConfigErrorAlarmTextLibrary" cannot be resolved.

The user-visible result is a placeholder token that looks similar to:

@ConfigErrorAlarmTextLibrary::OPCUACONN_FAIL_001
@ConfigErrorAlarmTextLibrary::OPCUACONN_FAIL_002
@ConfigErrorAlarmTextLibrary::OPCUACONN_LOST_004

Switching the runtime language only swaps the language lookup, not the CRef pointer. Therefore the symptom persists regardless of whether the operator selects Italian (IT) or English (EN).

Diagnostic Workflow with TraceView

Before applying the fix, confirm the diagnosis using the runtime trace viewer. TraceView is included with every WinCC Unified installation.

1. On the runtime PC, launch TraceView.exe from C:\Program Files\Siemens\Automation\WinCCUnified\bin\.
2. In the Source filter, select Alarms and Connection components.
3. Set the level to Information or lower.
4. Reproduce the failing OPC UA connection.
5. Look for the message The CRef for textlist "ConfigErrorAlarmTextLibrary" cannot be resolved.
6. Count the occurrences: each configured OPC UA client connection produces one entry.

Two occurrences of the trace entry confirm two failed OPC UA clients, matching the project configuration. The trace entry is the authoritative indicator that image version mismatch is the root cause.

Step-by-Step Resolution Procedure

Apply the correction on the engineering PC, recompile the project, and download to the runtime target.

1. Open the project in TIA Portal V17 Update 5. Verify the installed TIA Portal version under Help > About. The build string must report Update 5.
2. Navigate to the HMI device. In the project tree, expand Devices & Networks and select the Unified PC or Unified Comfort Panel that hosts the runtime.
3. Open the device properties. Right-click the device and select Properties, or click the device once and open the Inspector window.
4. Locate the Image / Runtime version property. In the Inspector window, navigate to Properties > General > Image / Runtime version.
5. Note the current setting. It typically reads 17.0.0.0 on projects created against the V17 GA image.
6. Change the image version. From the drop-down, select 17.0.0.1 (or whichever service level corresponds to your TIA Portal Update). Update 5 users select 17.0.0.5.
7. Confirm the prompt. TIA Portal warns that existing CRef pointers will be regenerated. Accept the warning.
8. Compile the project. Right-click the HMI device and select Compile > Software (rebuild all).
9. Download to the runtime. Right-click the device and select Download to device > Software (all). Tick Overwrite all on the dialog.
10. Restart the runtime. Either restart the WinCC Unified Runtime service or reboot the runtime PC.

Verification

Confirm the resolution by re-running the failure scenario:

1. Launch the runtime and reproduce the OPC UA connection failure.
2. Open the Alarm control and inspect the affected alarm row. The Message text column must show a localized sentence (for example "Connessione OPC UA non riuscita" in Italian or "OPC UA connection failed" in English).
3. Switch the runtime language from IT to EN. The text must change accordingly with no placeholder tokens.
4. Open TraceView. The message The CRef for textlist "ConfigErrorAlarmTextLibrary" cannot be resolved must no longer appear.
5. Export the alarm log and verify the text fields contain real strings, not @TextID tokens.

If the text remains a placeholder after step 6 of the procedure, re-check the image version of every Unified device in the project and repeat the compile-and-download cycle.

Understanding ConfigErrorAlarmTextLibrary

ConfigErrorAlarmTextLibrary is the WinCC Unified system text list that ships the localized strings for configuration and connection errors. The library is built into the runtime image and is not user-editable. It contains entries for the following alarm categories:

The text list is regenerated when the image version is upgraded. Older CRef pointers that no longer map to a valid entry fall through to placeholder rendering.

OPC UA Connection Alarms in WinCC Unified

The OPC UA client interface in WinCC Unified is one of the most common sources of system alarms in production installations. The interface is configured under Devices & Networks > [HMI Device] > OPC UA > OPC UA Clients. Connection alarms trigger in the following conditions:

• The OPC UA server endpoint is unreachable (network outage, firewall).
• The server certificate is untrusted (self-signed, expired, wrong CN/SAN).
• The session token expired (no keep-alive).
• The configured security policy is not supported by the server.

Each connection produces independent system alarms. With two OPC UA clients configured, two trace entries appear, two alarm rows appear, and (when image version is wrong) two unresolved text placeholders appear.

Compatibility Tool Usage

The Siemens TIA Portal compatibility tool confirms which operating systems are supported for each TIA Portal and runtime version. The user environment (Windows Server 2016 Standard Build 14393) is supported for TIA Portal V17 with restrictions:

• Windows Server 2016 is supported as engineering host up to TIA Portal V18. Support ends before V20.
• Server Core editions are not supported for WinCC Unified Runtime.
• Server 2016 with the Desktop Experience feature is required for runtime visualization.

Always verify the host operating system against the compatibility tool before installing an update. Incompatibility manifests as install errors and not as runtime placeholder text, but a stale compatibility profile can lead engineers to suspect the OS instead of the project image version.

Related Issues and Edge Cases

Several symptoms mimic the placeholder-text defect. Distinguish them by the failure layer:

Prevention and Update Best Practices

Apply the following practices when introducing a TIA Portal update into an active project:

1. Maintain a project upgrade checklist. For each TIA Portal Update, record the target image version that ships with the update.
2. Use a copy of the project for upgrade testing. Never upgrade the image version directly on the active production project.
3. Compile all Unified devices after an Update. Image version settings are device-specific and must be reviewed per device.
4. Export the alarm log baseline before upgrade. A pre-upgrade text dump allows comparison after upgrade.
5. Document the runtime image version in the project. Record it in the project properties or in a separate readme file for audit purposes.
6. Keep TraceView accessible. Place a shortcut on the engineering and runtime desktops.
7. Validate the compatibility tool entry. Cross-check the OS and TIA Portal version on every update cycle.
8. Schedule a runtime restart window. A full runtime restart is the cleanest way to flush stale CRef pointers after an image upgrade.

Troubleshooting Matrix

Field Commissioning Notes

When commissioning a new Unified PC system that runs OPC UA client connections, perform the following checks during the Site Acceptance Test (SAT):

1. Confirm the TIA Portal installed on the engineering PC reports the expected Update level.
2. Confirm the image version of every Unified device matches the Update level.
3. Force an OPC UA server outage and verify that the Alarm control shows localized text, not placeholders.
4. Switch runtime language and verify text changes.
5. Inspect TraceView for CRef resolution errors.
6. Save TraceView output as part of the SAT documentation.

Operational Considerations

Placeholders in operator-visible alarm text can mask real production faults. Operators trained to read Italian may disregard an unrecognizable token and fail to act on a real connection loss. After a TIA Portal update, the engineering team must:

• Verify that alarm text renders correctly in every supported runtime language.
• Communicate the change to operations, especially if the runtime language was previously mis-rendered.
• Update the operator training materials to reflect the corrected text strings.
• Retain a backup of the previous project version for rollback during the validation window.

Reference Paths

The following Siemens resources document the WinCC Unified system alarm subsystem and the configuration mechanics relevant to this defect. Use them as the engineering reference baseline.

• Configuring the status texts of alarms (RT Unified) - WinCC Unified
• System alarms Runtime (RT Unified) - WinCC Unified
• Siemens Industry Online Support: WinCC Unified text missing FAQ
• TIA Portal compatibility tool