Resolving WinCC V6.2 SP1 Insufficient License Error

1. Problem Overview

Engineers commissioning Siemens WinCC V6.2 SP1 frequently encounter a runtime startup error: the project loads into Runtime, then immediately reports "Insufficient License", and the tag counter collapses to the red DEMO state. Typical reported configuration: a single workstation PC holding both an RT (Runtime) 1024-tag license and an RC (Runtime/Configuration) 8192-tag license, with a project that only references roughly 600-800 process tags. The user-visible symptom is misleading: the project has more than enough licensed capacity, yet Runtime refuses to honour it.

This article consolidates the diagnostic and remediation paths for this class of fault. It is written against WinCC V6.2 SP1 but applies equally to the broader WinCC V6/V7 line, since the licensing engine, the tag-counting rules, and the runtime startup sequence are unchanged across these releases. Procedures also remain valid after migration to WinCC V7.5 / V7.5 SP1 and to TIA Portal's WinCC Professional option, with the caveat that the Automation License Manager (ALM) version and the entry point of the log files differ slightly.

2. WinCC V6.2 SP1 Licensing Architecture

WinCC licensing is handled by the Automation License Manager (ALM) service and validated at three points: project load, runtime activation, and tag-database compilation. Understanding the categories is essential because the wording "Insufficient License" can be triggered by any of the three.

Key rule: the project type (single-user or multi-user) and the license type (RT or RC/Server/Client) must match. The same PC can hold multiple licenses, but only one is selected by the WinCC runtime startup logic, and the choice is determined by the project's Computer Type property, not by which license is currently "active" in ALM.

When the chosen project type does not match the available license, WinCC silently downgrades the project to DEMO mode: Runtime starts, but the licensing banner in the lower right corner displays DEMO and runtime is restricted to the 1-hour evaluation window after each activation. Tag limit enforcement still applies, so even a small project will continue to be flagged if the licensing subsystem believes the configuration is invalid.

3. Tag Counting Rules: Internal vs External

WinCC distinguishes between three tag categories, and only one of them drives the licensing check:

• Internal Tags: variables that live entirely inside the WinCC database. They do not require a PowerTag license and do not contribute to the count shown in the licensing dialog.
• External Tags (PowerTags): variables connected to a PLC via a channel driver (S7, MPI, PROFIBUS, TCP/IP, OPC, etc.). Each configured external tag consumes one PowerTag from the license pool.
• Archive Tags: external tags additionally configured to be logged. They count as PowerTags exactly once; the archive tag itself does not consume an additional license unit.

The licensing check is performed on the External Tag count only. WinCC Explorer reports this in two places:

1. Status bar (bottom right): External Tags: 678 / License: 1024 while the project is open in the Explorer.
2. Tag Management dialog: the Channel/Connection tree shows the number of configured external tags per driver.

If the status bar shows the correct project count but the License value reads 0 or DEMO, the issue is licensing - not tag count. If the status bar shows a count higher than expected, audit the Tag Management tree: unconnected tags and tags inherited from a copy-paste of a larger project can silently inflate the count.

4. Root Cause Analysis: Why "Insufficient License" Appears

The WinCC V6.2 SP1 runtime startup sequence performs a license validation in this order:

1. Read the project's Computer Type property (single-user vs. multi-user server vs. multi-user client).
2. Query ALM for a compatible license matching that project type.
3. Compare the licensed tag bucket against the configured External Tag count.
4. If no match is found, fall back to DEMO mode and emit a startup entry in the license log.

The "Insufficient License" message is therefore triggered by any of four root conditions:

In the typical reported case (1024 RT + 8192 RC on one PC, ~678 tags), the root cause is almost always #1 or #3: a multi-user project type is consuming the slot, leaving only the multi-user RC license, and the 8192 bucket looks correct, but the runtime configuration does not match what the project expects. Switching the project to Single-User Project type, or moving the RT license onto the workstation where runtime actually executes, resolves it.

5. Diagnostic Procedure

1. Open the Diagnose folder. Navigate to the WinCC install path (default: C:\Program Files\Siemens\Automation\WinCC\Diagnose). Inspect license.log and license_info.log. Each contains a timestamped list of the licenses WinCC requested from ALM and the response received. A line such as License for XXXX not found or Falling back to DEMO points to the exact gap. Older WinCC versions wrote these files with German Fehler/Warnung prefixes if the host locale was German; this is normal and does not indicate a fault.
2. Read the project type. In WinCC Explorer, right-click the computer icon at the top of the project tree, choose Properties, and open the General tab. The Type field shows Single-User Project, Multi-User Server, or Multi-User Client. This single value is the most common cause of the issue.
3. Read the live licensing status. With the project still open in WinCC Explorer, look at the bottom right of the Explorer window. The line reads External Tags: NNNN / License: NNNN. Record both values.
4. Cross-check ALM. Open the Automation License Manager (Start → Siemens Automation → Automation License Manager). The "Active" pane shows every license currently recognised on this PC. The "Invalid" pane shows any license file that ALM considers corrupt, expired, or moved. Note the license numbers and tag buckets.
5. Verify the dongle (if applicable). RT/RC licenses ship as either software license files (placed under %ProgramData%\Siemens\Automation\License) or hardware dongles (the orange/red USB stick). Hardware dongles must be plugged in before WinCC Explorer or Runtime is started; hot-plugging will not register the license until the ALM service is restarted.
6. Compare against the project type. Apply the table from Section 4. If the project is Single-User but only an RC/Client license is present, that is the mismatch.

6. Resolution Path A: Single-User vs Multi-User Project

The single most common fix for the reported fault.

1. In WinCC Explorer, right-click the computer icon and choose Properties.
2. On the General tab, change Type of project to Single-User Project.
3. Click OK. WinCC will warn that the change cannot be undone without recreating the project; confirm only if you are sure.
4. Close WinCC Explorer, restart the Siemens ALM service, then re-open the project and start Runtime.

If the original project must remain multi-user (for example, you plan to attach Operator Stations later), skip this path and use Path B or Path C instead.

7. Resolution Path B: License Count vs License Type

If the project type is correct and a valid license is installed but the tag count still appears insufficient:

1. Confirm the license bucket is in fact the one WinCC selected. The status bar (External Tags: 678 / License: 1024) shows the bucket of the selected license. If the License field reads 0, no compatible license was found.
2. If the status bar reads, for example, License: 1024 and you actually have an 8192 RC license installed, the RC license has been ignored. Cause: WinCC selected the 1024 RT license because the project is Single-User; the RC license is being held as a fallback or is being used by another project on the same PC.
3. Two valid responses: either accept the 1024 limit (and reduce the project's external tag count below 1024) or upgrade the RT license to a larger bucket. RC licenses do not supersede RT licenses on a Single-User project.

For projects genuinely above 8192 tags, contact your Siemens sales channel for a custom RT bundle. The standard PowerTag buckets stop at 8192 in WinCC V6/V7; larger configurations are sold as a Server/Client configuration with a separate Server license.

8. Resolution Path C: Multiple License Conflict

When more than one compatible license is installed on the same PC, WinCC follows a deterministic selection order but the order has changed between V6 and V7. Common failure mode: an old evaluation license remains in %ProgramData%\Siemens\Automation\License and gets selected before the production license.

1. Open ALM. Move the unwanted license to the Invalid pane (drag and drop) or remove it entirely. Do not delete the production license.
2. Restart the ALM service.
3. Re-open WinCC Explorer and confirm the status bar shows the expected bucket.

If the license is locked to a different PC's dongle, it cannot be moved by drag and drop. Use ALM's License Key View → Manage to deactivate the license on the source PC and reactivate it on the target.

9. Verification and Commissioning Checks

After applying any of the above resolutions, perform the following sequence before declaring the fault closed:

1. License bar in Explorer: confirm License: NNNN shows the expected bucket and not 0 or DEMO.
2. License log review: open license.log in the Diagnose folder; the latest entry should show a successful match rather than a fallback.
3. Runtime startup: activate Runtime. The status bar must show the licensed tag count, not DEMO. Let the runtime sit for at least 10 minutes to confirm the evaluation timer has not started (if DEMO is engaged, Runtime silently terminates after 1 hour).
4. Service restart test: reboot the PC. A clean start with the license present is the only proof that the configuration is persistent.
5. Process value test: change a process value in the PLC and verify the corresponding WinCC tag updates. A DEMO-mode project that opens a previous project file from cache can appear to run normally for a few minutes; live data is the proof.

10. Common Pitfalls and Field-Notes

• Copy-pasted project files often retain the source computer's Type property. Even a 678-tag project copied from a server PC will start as a Server project on the new PC and will require an RC/Server license.
• Channel driver duplication: adding a second S7 channel does not double-count tags, but adding a second connection under the same channel can do so if a tag is bound to both. Audit Tag Management if the status bar count is unexpectedly high.
• OPC DA driver quirk: tags imported from an OPC server count as PowerTags even if the underlying PLC variable is later deleted from the OPC server. Clean unused OPC items in Tag Management before checking the count.
• Service account for ALM: the ALM service runs under LocalSystem by default. If you have a restricted user environment, ensure the service account has read access to %ProgramData%\Siemens\Automation\License.
• Antivirus interaction: some security products quarantine the CCLicense.exe file in the WinCC install directory. The licensing subsystem will then fail to start; whitelist the full WinCC install path before commissioning.
• Cross-version upgrade: if you migrate a project from V6.2 to V7.x without a fresh license, the project may run for 30 days in V7 demo mode even with a valid V6 license present. Confirm the V7 license separately.

11. Reference Parameter Summary