WinCC Flexible 2008 SP2 Simulation Buttons Not Working: Complete Troubleshooting Guide

Symptom: In WinCC flexible 2008 SP2, the Start Runtime System and Start Runtime System with Simulator toolbar buttons in the ES (Engineering System) suddenly stop launching the WinCC flexible RT. The buttons dim briefly, the Save button also greys out for a moment, but no *.RTF runtime is produced and no simulator window appears. Other projects (newly created) still simulate correctly on the same PC, isolating the problem to a single corrupted project file or to a stale state in the WinCC flexible 2008 SP2 development environment itself.

This reference documents the root cause hierarchy observed in field escalations, the exact repair sequence, and the verification steps that confirm the runtime is healthy again. It is written for HMI commissioning engineers and PLC integrators working with SIMATIC panels configured through Siemens Industry Online Support deliverables.

1. Affected Environment and Versions

2. Problem Description (Observed Behavior)

1. Engineer opens a previously working *.hmi WinCC flexible 2008 SP2 project.
2. Engineer clicks Start Runtime System (F5) or Start Runtime System with Simulator (Shift+F5).
3. The toolbar buttons dim. The Save button also greys out briefly. The status bar shows a transient message but no *.RTF is produced and no runtime window opens.
4. Creating a new project in the same WinCC flexible instance simulates normally. The defect is therefore project-scoped or start-center-scoped, not a global RT installation failure.
5. Symptom is intermittent: a previously saved project that simulated earlier in the same day no longer simulates after a few hours of editing, after a forced crash, or after Windows updates.

3. Root Cause Hierarchy

Five root causes have been confirmed across multiple engineering escalations. Apply the fixes in the listed order — the most common cause is listed first.

3.1 Corrupted WinCC flexible start center state

WinCC flexible 2008 SP2 stores user-specific state (recent project lists, last-open paths, project view cache) in the user's profile. When this XML-based state file becomes inconsistent, the ES can open the project but the action handlers wired to the simulation toolbar buttons are not registered, producing the dim-and-no-action behavior. This is the dominant root cause when a reboot does not resolve the issue but a different project still simulates correctly.

3.2 Stale temporary project files in the project directory

Each *.hmi project maintains a \tmp\, \lck\ and \backup\ subfolder. If WinCC flexible crashes (BSOD, forced task kill, power loss), these folders can retain an incomplete compile output that blocks subsequent recompiles. The simulation button fails silently because the compile prerequisite step does not complete.

3.3 Project file references orphaned integrated components

References to a deleted or renamed ProTool project, an OPC Scout configuration, or a STEP 7 / SIMOTION integrated project can leave dangling pointer entries in *.hmi. WinCC flexible 2008 SP2 attempts to resolve these references on every compile and aborts without surfacing an error dialog when the project was opened silently via the recent files list.

3.4 WinCC flexible RT service cache in a bad state

WinCC flexible 2008 SP2 installs two Windows services: CCAgent and CCEServer. The simulator talks to CCAgent over local DCOM. When CCAgent holds a stale license handle or its %PROGRAMDATA%\Siemens\Automation\WinCC flexible 2008\Runtime cache is corrupted, the simulator launch returns a non-fatal error to the ES and the button appears to do nothing.

3.5 User rights / DCOM permissions on the local PC

If the user account was changed (domain migration, UAC elevation, or Local Users and Groups cleanup), the DCOM launch permissions on CCAgent.exe can be lost. The toolbar buttons run synchronously, fail to instantiate the RT process, and time out silently. This is the most common cause on Windows 7 x64 after a Windows Update cycle that resets DCOM defaults.

4. Diagnostic Workflow

Run the following checks before applying any fix. Each test isolates one root cause from the list above.

1. Recent files test: Close the broken project. Use File → Open (do not use the recent files list) and reopen the same *.hmi. If simulation now works, the root cause is the start-center state (cause 3.1).
2. New project test: Create an empty project with one screen and one button. Attempt simulation. If it succeeds while the original project still fails, the root cause is project-scoped (3.2 or 3.3).
3. Service status check: Open services.msc and verify SIMATIC WinCC flexible CCAgent and SIMATIC WinCC flexible CCEServer are Running with Automatic startup. If CCAgent is stopped, start it manually and retry simulation (cause 3.4).
4. DCOM permission check: Run dcomcnfg → Component Services → Computers → My Computer → DCOM Config. Locate the CCAgent application, open Properties → Security, and confirm the launching user has Local Launch and Local Activation rights. Reset using the defaults if unsure (cause 3.5).
5. Compile output inspection: Open the project, press Project → Compiler → Check Consistency. Any error referencing an unresolved tag, screen, or alarm must be resolved before the simulation buttons will operate.

5. Solution Sequence (Apply in Order)

5.1 Step 1 — Clear temporary files inside the affected project

1. Close WinCC flexible 2008 SP2 completely, including the start center.
2. Open Windows Explorer and navigate to the project folder.
3. Delete the contents of the following subfolders (do not delete the folders themselves):
   • \tmp\
   • \lck\
   • \backup\
   • \MetaTags\ (only if present and if you have a backup)
4. Inside the project folder, also delete the *.RTF, *.log, and *.bak files generated by the last compile attempt.
5. Reopen the project and choose Options → Delete temporary files from the menu to clear any internal caches the ES holds in memory.
6. Choose Project → Compiler → Rebuild All and verify the compile finishes without errors.
7. Click Start Runtime System with Simulator. The simulator window should appear within 5–10 seconds on a typical engineering PC.

5.2 Step 2 — Reset the WinCC flexible 2008 SP2 start center

If step 1 did not restore simulation, the start-center state itself is corrupted. Reset it as follows:

1. Close WinCC flexible 2008 SP2 completely.
2. Open Start → Programs → Siemens Automation → SIMATIC → WinCC flexible 2008 → WinCC flexible. Right-click the shortcut and choose Properties.
3. In the Shortcut tab, locate the target path. The reset switch is invoked by appending a flag to the executable.
4. Modify the target to:

   "C:\Program Files\Siemens\Automation\WinCC flexible 2008\HMI\HmiES.exe" -resetcenter

5. Launch the shortcut once. The start center opens with default factory state. Close it.
6. Restore the original target line (remove the -resetcenter flag) so future launches behave normally.
7. Reopen the project via File → Open (not via the recent files list) and attempt simulation.

The reset restores default user preferences, recent project lists, view layouts, and the registry entries the simulation action handlers depend on. The reset does not delete any project data; it only affects the %APPDATA%\Siemens\Automation\WinCC flexible 2008 user profile.

5.3 Step 3 — Repair the WinCC flexible 2008 SP2 installation

If the toolbar buttons still fail after steps 1 and 2, repair the installation to replace corrupted runtime binaries and DCOM configuration files:

1. Open Control Panel → Programs and Features.
2. Select SIMATIC WinCC flexible 2008 SP2 and click Repair. Accept the prompt to retain license keys.
3. Reboot the PC when the repair finishes.
4. After reboot, verify both CCAgent and CCEServer services are Running in services.msc.
5. Reopen the project and attempt simulation.

5.4 Step 4 — Re-register the DCOM application IDs

If simulation still fails, the DCOM AppIDs for WinCC flexible components may be unregistered. Repair normally fixes this, but on a heavily customized Windows 7 image the fix is incomplete.

1. Open an elevated command prompt (Run as administrator).
2. Navigate to the WinCC flexible 2008 binary folder:

   cd "C:\Program Files\Siemens\Automation\WinCC flexible 2008\HMI"

3. Re-register the runtime server DLLs:

   regsvr32 /s CCEServer.dll
   regsvr32 /s CRtxAgent.dll
   regsvr32 /s HmiRTm.exe

4. Reboot the PC.
5. Retry simulation.

5.5 Step 5 — Recreate the project from an integrated backup

If the project itself is corrupted and cannot be repaired, use the most recent *.hmi.bak backup file. WinCC flexible 2008 SP2 stores rolling backups in the \backup\ subfolder.

1. Open Windows Explorer and navigate to <project>\backup\.
2. Identify the most recent *.hmi.bak file with a timestamp matching the last known good compile.
3. Copy the file to the project root and rename it <project>.hmi (after backing up the broken file).
4. Reopen the project. Recompile and attempt simulation.

6. Verification Procedure

After applying any of the solutions above, run the following verification checklist before returning the engineering station to the developer.

1. Start center launches: Open WinCC flexible 2008 SP2 and confirm the start center renders the recent files list correctly. If the recent files list is empty after a reset, this is expected behavior; the list will repopulate as projects are opened.
2. Toolbar button responsiveness: Open the previously broken project. Click Start Runtime System with Simulator. The button should not dim without producing a runtime; the simulator window should appear within 10 seconds.
3. Tag simulation works: In the simulator, change a tag value via the simulator control panel. Confirm the value updates in the active screen.
4. Alarm simulation works: Trigger a configured alarm from the simulator and confirm the alarm view populates.
5. Compile cycle: Stop the runtime, return to the ES, modify a property on any object, and recompile. The compile should complete without errors and the toolbar button should immediately re-arm.
6. Service health: Open services.msc and confirm CCAgent and CCEServer are still Running. They should remain running between simulation sessions.
7. Event log review: Open Event Viewer → Windows Logs → Application and filter for source CCAgent or HmiES. No error events with timestamp matching the last simulation attempt should be present.

7. Parameter and Service Reference

8. Common Error Patterns and Mappings

9. Preventive Maintenance Recommendations

• Local project storage: Keep WinCC flexible 2008 SP2 *.hmi files on a local NTFS volume, not on a network share. Network latency and dropped connections are the most common silent cause of corrupted compile output.
• Exclusion list: Configure Windows Defender or any third-party AV to exclude %APPDATA%\Siemens, %PROGRAMDATA%\Siemens, and the project root folder. Real-time scanning of the *.RTF and *.hmi files during compile produces exactly the dim-and-no-action symptom described in this article.
• Scheduled service restart: Create a weekly scheduled task that restarts the CCAgent and CCEServer services. Both are stable for days at a time, but periodic restarts eliminate stale license handles and prevent the issue from surfacing during commissioning.
• Project baseline backup: After every successful simulation, copy the *.hmi to *.hmi.bak in the same folder. WinCC flexible 2008 SP2 keeps only 5 generations; an additional manual baseline guarantees a recovery point.
• Disable Windows Search indexing on the project folder. Search indexer interference with *.hmi and *.RTF can also produce the same dim-and-no-action symptom.

10. Migration Path to TIA Portal

WinCC flexible 2008 SP2 is in the Siemens product lifecycle phase "discontinued" for new sales, with support delivered through Service Pack hotfixes. If the engineering station must continue running a long-term program, migrate the HMI configuration to TIA Portal V17 or later:

1. In WinCC flexible 2008 SP2, choose Project → Migration → Migrate project to TIA Portal. The wizard produces a *.ap17 archive.
2. Open TIA Portal and import the archive. Confirm that all panels, tags, alarms, and screens resolve without errors.
3. Switch to the TIA Portal RT simulation model. Note that the toolbar buttons described in this article do not exist; the equivalent operations are Online → Simulation → Start and the panel simulator integrated with TIA Portal.
4. For Basic Panels, review the function key behavior in Function Keys (Basic Panels) - WinCC to confirm globally assigned keys trigger the same action on the HMI device and PLC regardless of the displayed screen.

Function key assignments migrate 1:1 from WinCC flexible 2008 SP2 to TIA Portal for OP 77, TP 177, and OP 170 projects. For MP 277 / MP 377 / Comfort Panel projects, the migration tool emits a warning that must be reviewed manually because K-TP function key F-keys have different PLC address mapping in TIA Portal.

11. Frequently Asked Questions