Troubleshooting WinCC Trial License Expiration Popups Across ES, OS Servers, and Clients in SIMATIC PCS 7

A recurring runtime error popup stating 'License key not found' or 'Trial license expired' appearing simultaneously across the Engineering Station (ES), OS Servers, and OS Clients in SIMATIC PCS 7 indicates that a 14-day or 21-day trial/demo license installed during commissioning has expired, or that a purchased permanent license key is missing, corrupted, or installed in an incorrect license category. When a trial license lapses, WinCC initiates periodic modal warning dialogs that interrupt operator interactions. To resolve this, open Automation License Manager (ALM) on each workstation, locate and remove expired trial keys, and transfer valid permanent Floating or Single runtime licenses.

PCS 7 and WinCC Licensing Architecture and Trial Key Mechanics

SIMATIC PCS 7 relies on Automation License Manager (ALM) to authenticate software entitlements. Siemens software packages include temporary Trial Licenses (typically valid for 14 or 21 days) intended exclusively for testing and initial hardware commissioning:
* Trial Key Expiration: The trial period begins the moment the licensed software package is first launched. Once the countdown reaches zero days, the license status transitions to Expired.
* Global System Impact: If an engineering team deployed trial licenses across the Multiproject images (ES, redundant OS Servers, and OS Clients) without transferring permanent license certificates, all stations reach expiration simultaneously.
* Runtime Behavior: WinCC does not shut down running controllers or halt process graphics immediately; instead, it enforces periodic intrusive modal warning popups ('WinCC License Error') every 10 minutes, disrupting operator control.

Diagnostic Inspection via Automation License Manager (ALM)

To pinpoint which software package or station is missing permanent authorization:
1. On each affected machine (ES, OS Server 1, OS Server 2, OS Clients), open Automation License Manager (ALM).
2. Select the local drive: C:\ -> click the table header License Type to group licenses.
3. Review the column License Type:
* Any entry marked Trial with status Expired or remaining time 0 days is triggering the popups.
* Verify whether the required permanent license (e.g. Single, Floating) is present on the drive.
4. Check the license count against consumed Process Objects (PO):
* In SIMATIC Manager, check Options -> Process Objects -> Display... to verify AS RT PO and OS RT PO counts.

Remediation Procedure - Removing Trial Keys and Installing Permanent Licenses

Follow this procedure to eliminate trial expiration popups across all stations:

[Phase 1: Remove Expired Trial Keys]
   │  • Open Automation License Manager (ALM) as Administrator
   │  • Select: View -> Manage -> Check "Show all license keys"
   │  • Locate expired "Trial" licenses (e.g. "SIMATIC WinCC Server Trial")
   │  • Right-click the expired trial license -> Select: "Delete"
   │    (Deleting the dead trial allows ALM to search for valid permanent keys)
   │
[Phase 2: Transfer Permanent License Keys]
   │  • Insert the official Siemens USB License Key drive containing permanent licenses
   │  • In ALM, drag and drop the required permanent keys onto the local C:\ drive:
   │      - OS Server: SIMATIC WinCC Server (6AV6371-1CA07-4AX0)
   │      - OS Server: SIMATIC WinCC Redundancy (6AV6371-1CF07-4AX0)
   │      - OS Server: SIMATIC PCS 7 OS Software Server Runtime (6ES7658-2BA08-0YB0)
   │      - OS Client: SIMATIC WinCC Client (6AV6371-1CA07-4AX0)
   │
[Phase 3: Refresh License Service]
   │  • In ALM: Select menu "License Key -> Check"
   │  • Restart the "Automation License Manager Service" in Windows Services (services.msc)
   │  • Restart WinCC Runtime to clear the cached trial alarm flag

Procurement Notice: Validate all final license quantities, media packages, and part numbers against current Siemens Industry Mall catalogs and with an authorized Siemens distributor quotation prior to procurement.

Station Licensing Requirements and License Type Matrix

Verify that each physical workstation in the PCS 7 architecture holds its designated permanent license entitlements:

Station RoleRequired Software LicensesMLFB ExamplePermitted License TypeEngineering Station (ES)PCS 7 Engineering AS/OS, Version Trail6ES7658-5AA08-0YA5Floating / Single (RC)OS Server (Primary)PCS 7 OS Server RT PO, WinCC Server, Redundancy6ES7658-2BA08-0YB0Single / Floating (RT)OS Server (Standby)PCS 7 OS Server RT PO, WinCC Server, Redundancy6ES7658-2BA08-0YB0Single / Floating (RT)OS Client WorkstationSIMATIC WinCC Client RT, OS Client License6AV6371-1CA07-4AX0Single / Floating (RT)Maintenance StationSIMATIC PCS 7 Maintenance Station RT6ES7658-7GB08-0YB0Single / Floating

Verification

To confirm that WinCC licensing errors are resolved:
1. In Automation License Manager on each machine, verify that the License Key list contains zero 'Trial' entries with 'Expired' status.
2. In WinCC Explorer, open the project and activate Runtime.
3. Observe the system for a minimum of 30 minutes; confirm that no 'License key not found' or 'Trial license expired' dialog popups appear.
4. Open the WinCC Alarm Logging list; verify that system message @1000002 (WinCC Demo Mode) is not present.
5. In ALM, select Target System -> Connect Computer; verify from the ES that all networked servers and clients display valid license compliance.

Limitations and Operational Precautions

Never use unauthorized third-party key generators or crack utilities. Such utilities corrupt the internal cryptographically signed Siemens license database (AX NF ZZ), leading to hard-to-diagnose communication failures and invalidating manufacturer support contracts. For redundant OS Server configurations, both Server A and Server B must have identical independent permanent license packages; redundancy options are not shared across servers.

Engineer FAQ

Why did the license error appear on all stations at the same time?

If the systems were commissioned simultaneously using trial licenses installed from the PCS 7 installation media, all stations reach their 14-day or 21-day expiration date concurrently.

Does WinCC stop controlling valves and motors when the trial license expires?

No. The AS controllers execute process logic independently. However, WinCC SCADA enters demo mode, displaying intrusive warning popups that hinder operator visibility and manual operations.

Can I move a permanent license key over the network?

Yes. Automation License Manager allows transferring floating licenses across the Terminal Bus from a central license server to client workstations via License Key -> Transfer.

What is the difference between an RC and an RT license?

An RC (Runtime + Configuration) license allows both project engineering in Graphics Designer/SIMATIC Manager and runtime execution. An RT (Runtime) license permits runtime execution only.