Resolving OS Compilation Startup Failure and Immediate s7uvmapx.exe Termination in PCS 7

In SIMATIC PCS 7 (v8.0, v8.1, v8.2, and v9.0), when initiating an OS compile and the compiler process (s7uvmapx.exe) starts in Windows Task Manager but terminates abruptly after a few seconds without displaying the compilation wizard or generating error logs, the failure is caused by stale project database locks (.lok, .ldf), an invalid WinCC project registration within the Multiproject, or corrupted AS-OS Engineering communication files following project archiving/retrieval. To resolve this, run 'reset_wincc.vbs' from the WinCC\bin directory to release background database handles, perform 'File > Save As... (with reorganization)' on the Multiproject, or temporarily remove the OS station from the Multiproject and re-integrate it via 'Add to Multiproject'.

Mechanism of the s7uvmapx.exe Compilation Launcher

In SIMATIC PCS 7, the compilation of an Operator Station is initiated from SIMATIC Manager by right-clicking the OS object and selecting Compile. This action launches the AS-OS Engineering coordinator process:
$$\text{Process Executable: } \texttt{s7uvmapx.exe}$$

The initialization sequence of s7uvmapx.exe executes several mandatory pre-compilation checks before rendering the OS Compilation Wizard:
1. Multiproject Verification: Verifies cross-project references between the AS project (*.s7p), the central library, and the OS project (*.mcp).
2. Database Accessibility: Queries Microsoft SQL Server to confirm that the WinCC master database (<OS_Name>.mdf) is accessible and not in single-user mode or locked by another workstation.
3. Registry and DCOM Binding: Establishes local COM/DCOM interfaces between STEP 7 communication wrappers and the WinCC database access layer (s7opasbx.dll).
4. License Validation: Verifies that the engineering station possesses a valid AS-OS Engineering license in Automation License Manager (ALM).

If any of these fundamental checks fail during the first 3 to 5 seconds, s7uvmapx.exe encounters an unhandled exception and terminates silently, causing the Windows wait cursor to disappear without an error prompt.

Root Causes of Silent OS Compile Abortion

When other projects (such as APL_Example_EU) compile normally on the same PC, the engineering software installation itself is functional. The silent abort on a specific project stems from project-level anomalies:

Stale Lock Files Following Project Archive/Retrieve: When a project is archived while WinCC Explorer or SIMATIC Manager is open, lingering lock files (such as *.lok, .ldf locks, or hidden .dcf files in the wincproj directory) are packed into the zip archive. Upon retrieval, these stale locks cause s7uvmapx.exe to assume another instance is actively modifying the project.
Invalid OS Station GUID / Multiproject Desynchronization: If team members share virtual machines (VMs) or copy OS folders between directories, the internal unique identifier (GUID) linking the SIMATIC Manager OS object to the WinCC .mcp file becomes invalid.
SQL Server Database Suspect or Recovery State: If the VM was powered down abruptly, the WinCC SQL Server instance may flag the project database as In Recovery or Suspect.
Damaged transfer.log / s7asdoax.log File Handles: Read-only attributes or permission corruption on diagnostic log files prevent the compiler process from creating its runtime execution log.

Step-by-Step Diagnostic and Recovery Workflow

Execute the following progressive troubleshooting steps to restore OS compilation:

Step 1: Terminate Hanging Processes with reset_wincc.vbs

Close SIMATIC Manager and all open engineering applications.
Open Windows Start menu, type Run, and execute:
cmd "C:\Program Files (x86)\Siemens\WinCC\bin\reset_wincc.vbs"
A command prompt window opens and systematically terminates hanging WinCC processes (CCExpOp.exe, s7uvmapx.exe, CCAlgRtServer.exe) and releases database locks.
When the pop-up notification confirms completion, restart the computer or virtual machine.

Step 2: Delete Stale Lock and DCF Files

Using Windows Explorer, navigate to the OS project directory:
$$\text{\\wincproj\}$$
Delete any temporary files with the following extensions:
- *.lok (Lock files)
- <OS_Name>.dcf (Database connection file; WinCC regenerates this automatically)
- *.tmp
Verify that none of the files in the folder have the Windows Read-only attribute set.

Step 3: Remove and Re-integrate the OS Station

If s7uvmapx.exe continues to terminate immediately:
1. In SIMATIC Manager, select the OS station inside the Multiproject tree.
2. Select menu File > Multiproject > Remove from Multiproject. (Ensure you select 'Remove from Multiproject'—do NOT select Delete, which erases files from disk!).
3. In SIMATIC Manager, select File > Save As....
4. Check the box With Reorganization (Slow). This rebuilds the internal STEP 7 database pointers and purges orphan records.
5. Once reorganization completes, select File > Multiproject > Add to Multiproject....
6. Browse to the OS station project folder and select the project file (*.s7p).
7. Right-click the newly re-integrated OS station and click Compile. The OS Compilation Wizard will now open successfully.

OS Compilation Startup Failure Diagnostic Matrix

The following matrix details common symptoms, causes, and corrective actions for OS compile launch failures:

Observed SymptomPrimary Root CauseCorrective Actions7uvmapx.exe starts and exits after 3sStale .lok or .dcf lock files in projectRun reset_wincc.vbs; delete <OS_Name>.dcf from wincprojWindows wait cursor disappears silentlyOS station GUID mismatch in MultiprojectRemove OS from Multiproject, run 'Save As with Reorganization', re-add OSWizard fails to open on all projectsCorrupted AS-OS Engineering installationReinstall AS-OS Engineering package from the PCS 7 DVD setupSQL Server error logged in Windows Event LogWinCC SQL database in 'Suspect' stateAttach database using SQL Server Management Studio or restore clean backupMissing license pop-up occursExpired or missing AS-OS Engineering licenseCheck Automation License Manager for PCS 7 AS-OS Engineering key

Verification

To confirm that the OS compilation launcher is fully restored:
1. In SIMATIC Manager, right-click the OS project and select Compile.
2. Verify that the Compile OS wizard window opens promptly without crashing.
3. Advance through the wizard steps: Verify that the AS controllers and WinCC S7 Named Connections are correctly listed in the connection assignment table.
4. Select Changes only (or Entire OS) and click Compile.
5. Monitor Windows Task Manager: s7uvmapx.exe and CCExpOp.exe must remain active and perform database transfers until the compilation log reports completion.

Limitations and Operational Precautions

Observe the following precautions when troubleshooting OS compile issues:
- Never Delete the Entire wincproj Folder: The wincproj folder contains the core WinCC project database (*.mdf), process graphics (*.pdl), and scripts. Only delete temporary files (*.lok, *.dcf).
- Archive While Applications Are Closed: Never create project zip archives while SIMATIC Manager, CFC, or WinCC Explorer is running. Always close all Siemens software before archiving to prevent corrupted lock states.
- Virtual Machine Snapshots: Before performing database resets or project reorganizations on virtual machines, take a VM snapshot to ensure a clean recovery point is available.

Engineer FAQ

Why did s7uvmapx.exe work on the sample project but fail on my main project?

This proves the Siemens software installation is intact. The failure is isolated to project database locks (.dcf, .lok) or corrupted internal references between SIMATIC Manager and the WinCC project directory.

What does the .dcf file do in WinCC?

The .dcf (Database Configuration File) stores dynamic connection strings and parameters for the WinCC Microsoft SQL Server database. If corrupted, deleting it is safe because WinCC recreates it automatically on the next launch or compile.

Does 'Remove from Multiproject' delete my WinCC screens?

No. 'Remove from Multiproject' merely disconnects the project pointer from the master multiproject container. The actual folder, pictures (.pdl), and database files remain untouched on the hard drive.