Resolving STARTER Project Write-Protected Error on SINAMICS

Resolving STARTER "Project is Write-Protected or Already in Use" Error on SINAMICS Drives

Siemens STARTER (SIMATIC Automation Tool for Engineering and Commissioning) is the primary commissioning and parameterization software for the SINAMICS drive family — S110, S120, S150, G110, G120, G120C, G120D, G120P, G130, G150, GM150, and SM150. The tool is typically installed alongside SIMATIC STEP 7 (V5.x) for PROFINET/PROFIBUS integration or TIA Portal for newer architectures. A recurring commissioning-day failure occurs when STARTER refuses to open any locally created project with the message:

"The project is write-protected or is already being used by another process on a different computer."

The same error appears whether the user attempts to open an existing project, re-open a project that was just closed, or even open a brand-new project that has just been created on the local machine. The same user on the same PC can, however, successfully open pre-built example projects downloaded from Siemens Product Support. This document describes the root cause, the proven fix, and the diagnostic procedure for every reported variation of this failure.

1. Problem Definition and Symptom Matrix

The fault is non-destructive: the on-disk project files are intact, but the STARTER user interface cannot acquire a write lock on the project database. The error dialog halts commissioning and persists across reboots, which is why it is typically escalated to engineering support on day one of a drive start-up.

The differential observation — "I cannot open locally created projects, but I can open Siemens example projects" — is the most important diagnostic clue. It isolates the failure to the local project-creation pathway, not the file format itself.

2. Affected Software Versions and Windows Platforms

The fault has been confirmed on the following combinations. Use this table to confirm your installation is in scope before applying the fix.

3. Root Cause Analysis

STARTER stores every project as a Microsoft Access (Jet/ACE) database wrapped by a master control project file (.mcp). To open or create a project, STARTER must load the Microsoft Office Database Engine ODBC driver from the local Windows installation. The driver is normally installed side-effect by any Office suite (Office 2003, 2007, 2010, 2013) and is registered as the OLE DB / ODBC provider named "Microsoft Access Driver (*.mdb)".

When Microsoft Office is upgraded, repaired, or partially uninstalled, the registration of the Access Database Engine driver is corrupted, removed, or replaced with a 64-bit version while STARTER (a 32-bit application) requires the 32-bit provider. The ODBC connection STARTER attempts during project-open therefore fails silently. STARTER interprets the failed connection as "another process already owns the database" and returns the write-protected error.

3.1 Why Example Projects Still Open

Siemens example projects (downloaded from the Siemens Product Support / A&D support site) are distributed in a slightly different file layout and, on some STARTER builds, are imported through a path that does not require the same ODBC connection sequence. Locally created projects invoke the full Jet/ACE read-write path, which exposes the broken driver registration.

3.2 Why a Different PC Opens the Same Project

The project file on disk is valid. A different PC with a healthy Office Data Connectivity installation can open it without modification. The fault is therefore entirely client-side, and the project does not need to be repaired, re-zipped, or regenerated.

3.3 The Microsoft Office Upgrade Trigger

Field reports consistently trace the fault to one of the following Office lifecycle events:

• Uninstall of Office 2007 32-bit followed by install of Office 2010 64-bit (or vice versa).
• In-place upgrade of Office 2010 to Office 2013.
• Migration to Office 2016 / Office 365 Click-to-Run (which does not install the legacy Jet/ACE provider by default).
• Repair of Office that resets the data-connectivity component to a 64-bit build on a 32-bit STARTER host.

4. Solution — Install / Repair the Microsoft Office Database Engine

The verified, Siemens-endorsed fix is to install the Microsoft 2007 Office System Driver: Data Connectivity Components. This redistributable reinstalls the 32-bit ACE/Jet provider that STARTER requires, regardless of which Office version is currently installed.

4.1 Required Download

Download the driver from the official Microsoft download center:

Microsoft 2007 Office System Driver: Data Connectivity Components (File name: AccessDatabaseEngine.exe — ~25 MB).

4.2 Step-by-Step Repair Procedure

1. Close STARTER, SIMATIC Manager, and TIA Portal completely. Verify in Task Manager that no S7STARTER.exe, S7WanaEX.exe, or AccessDatabaseEngine processes remain.
2. Open Control Panel → Programs and Features. Identify the currently installed Office version and architecture (32-bit vs 64-bit). Record it.
3. If the system has both a 32-bit and a 64-bit Office installation (rare, but a known trigger), uninstall the 64-bit Office and reinstall the 32-bit version. STARTER is a 32-bit process and requires a 32-bit ACE provider in the SysWOW64 ODBC tree.
4. If Office was recently upgraded (e.g., 2007 → 2010, 2010 → 2013, 2010 → 2016/365), run an Office Repair from Control Panel → Programs and Features → Microsoft Office → Change → Online Repair. Online Repair is preferred because it resets the data-connectivity components to a known-good state.
5. Download AccessDatabaseEngine.exe from the link in 4.1.
6. Right-click the installer and select Run as administrator. Accept the license terms and complete the install with default options.
7. Reboot the PC. The driver registration in HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ODBC\ODBCINST.INI\Microsoft Access Driver (*.mdb) must now be present.
8. Launch STARTER and attempt to open the previously failing project.

4.3 Secondary Workaround — Delete the .mcp Lock File

If the Access driver repair cannot be performed immediately (for example, on a customer site without administrator rights), a transient workaround exists. STARTER writes a per-project lock file in the same directory as the project. Removing this file can clear the "already in use" state:

1. Close STARTER.
2. Navigate to the project directory, e.g., D:\Projects\MySinamicsLine\.
3. Locate the master control project file: project.mcp (or your project name with .mcp extension).
4. Right-click the file → Properties. If the Read-only attribute is set, clear it.
5. Delete the file. STARTER will regenerate it on next open.

5. Verification Procedure

After applying the fix, perform the following checks in order. Each must pass before commissioning proceeds.

5.1 ODBC Driver Registration Check

1. Open ODBC Data Sources (32-bit) from %windir%\SysWOW64\odbcad32.exe. On 64-bit Windows, you must use the 32-bit administrator — STARTER is a 32-bit process.
2. Click the Drivers tab.
3. Confirm the entry "Microsoft Access Driver (*.mdb)" is listed with a version of 12.00.xxxx or later.
4. If it is missing, the install in Section 4 failed — rerun AccessDatabaseEngine.exe as administrator.

5.2 STARTER Project Round-Trip Test

1. Launch STARTER.
2. Create a brand-new project: Project → New → Standard Project with SINAMICS S120 (or your target drive family).
3. Accept the default offline configuration. Save the project.
4. Close STARTER.
5. Re-launch STARTER and re-open the project just created. The write-protected error must not appear.

5.3 Drive Connectivity Test (Optional, Requires Hardware)

1. With the project open, select Target system → Online → Connect to target system.
2. Choose the PROFIBUS or PROFINET interface configured for the SINAMICS CU320-2 / CU310-2 / Control Unit.
3. Confirm the online connection establishes and drive parameters are readable.

6. Variant Case — DIGSI 4.87 + STARTER Coexistence

A separate but related failure has been reported when DIGSI 4.87 (Siemens SIPROTEC 4 protection relay configuration tool) is installed on the same PC as STARTER. The user observes that a "Device" folder appears inside the STARTER project tree, in which SIPROTEC devices can be added. Locally created projects containing this folder fail to open; Siemens-distributed example projects (which do not contain the folder) open without issue.

The root cause is a DLL conflict between DIGSI and STARTER in the COM/OLE registration path. The reported mitigations are:

• Run STARTER on a clean partition without DIGSI installed.
• Run DIGSI inside a virtual machine if both tools are required on the same engineering laptop.
• Contact Siemens Product Support for the STARTER 4.4 / 4.5 hotfix that resolves the COM registration conflict.

Before applying the Office-driver fix, verify that DIGSI is installed via Control Panel → Programs and Features. If DIGSI is present, the Access Database Engine fix alone will not resolve the issue; the DIGSI coexistence remediation must also be performed.

7. Cross-Platform — STARTER on Virtual Machines

Field engineers frequently use Windows XP Mode or a dedicated Windows XP virtual machine to host legacy STARTER 4.2 installations. A project that opens on the XP VM may fail to open on the Windows 7 host, and vice versa, purely because of the Office driver state on each OS image.

Recommended practice for multi-OS STARTER workflows:

• Maintain a one-line version matrix in the project folder documenting STARTER build, STEP 7 build, and Office version per OS image.
• Keep the Access Database Engine installed on every OS image that may host STARTER, even if Office itself is not installed.
• Do not share the project folder across an OS boundary using sync tools (OneDrive, Dropbox) while STARTER has the project open — the file-locking semantics of the Jet/ACE engine are not network-safe.

8. Diagnostic Decision Matrix

Use this matrix to triage the failure in the field when the standard fix is not yet applied.

9. Preventive Hardening for Future Office Upgrades

Engineering laptops that host STARTER should be considered "controlled-configuration" assets. The following baseline prevents recurrence during the next Office lifecycle event:

1. Document the Office architecture (32-bit vs 64-bit) in the engineering laptop's configuration record. STARTER is 32-bit, so Office 32-bit is the supported combination.
2. Disable Click-to-Run Office 365 installations on STARTER hosts. Use the MSI (machine-installer) Office 2016/2019 Volume License edition instead, which preserves the legacy data-connectivity components.
3. Block Windows Update from silently installing the 64-bit ACE provider. The 64-bit provider does not register in the 32-bit ODBC tree used by STARTER and produces a silent regression.
4. After any Office service pack or major upgrade, re-run the verification in Section 5.1.
5. Snapshot the engineering laptop before commissioning trips so the driver state is known-good at the start of every site visit.

10. Frequently Asked Questions