Resolving SIMOTION Scout Project Navigator Disabled After Install

1. Problem Definition

SIMOTION SCOUT is the engineering framework used to commission, program, and diagnose the Siemens SIMOTION motion-control platform (D410, D425, D435, D445, D455, and the C230-2 / P320 controllers). The application is delivered as a STEP 7 add-on and depends on the SIMATIC Manager runtime to host its project tree, libraries, and the workbench catalog. Under specific conditions, the SCOUT installer reports a clean completion (no installer error, no rollback, no MSI warning), the program launches, the splash screen resolves, and the SIMATIC Manager shell opens — yet the Project Navigator entry remains disabled (greyed out) in the menu, in the toolbar, and inside the right-click context of the project tree. Because the Project Navigator is the gateway to hardware configuration, technology objects, drive assignment, axis configuration, and the program/servo trace tools, the workstation is effectively unusable for any engineering task.

The failure is PC-specific: the same installation media and the same license key activate SCOUT correctly on other machines, and SCOUT can be uninstalled and reinstalled on the affected PC without resolving the issue. The behaviour has been confirmed on both Windows XP Service Pack 2 and Windows XP Service Pack 3 hosts, and is independent of the SIMOTION firmware version installed on the connected controller.

2. Affected Versions and Platform

For official product lifecycle and download references, consult the SIMOTION SCOUT product support page and the SIMOTION SCOUT V5.x operating instructions (entry ID 109751469). Note that SCOUT V4.x is out of regular maintenance and SCOUT V5.0/V5.1 reached end of active support — engineers maintaining legacy machines should still be able to obtain the corrective file set described below from the installed media.

3. Root Cause Analysis

The Project Navigator becomes disabled when SCOUT cannot resolve its registered workbench. The workbench registry is owned by the STEP 7 add-on manager and is materialised in two physical locations:

1. A binary registration record written by the SCOUT installer to C:\Program Files\Siemens\Step7\u7umc\data\wrkbnch\UESPersi.dat. This file caches the unique identifier of every registered workbench (SIMOTION, SIMATIC, COMOS, S7-Tech, …) together with its COM class ID, version stamp, and host machine fingerprint.
2. A COM / shell integration entry under HKEY_LOCAL_MACHINE\SOFTWARE\Siemens\Automation\Workbench\Instances and the corresponding HKCU mirror for the logged-in user.

If the UESPersi.dat file is left over from a previous, partially-uninstalled or interrupted install, it is loaded by SCOUT at startup. SCOUT compares the cached fingerprint with the live registry. When the comparison fails, SCOUT does not re-register the workbench — it simply hides every dependent command, including Project Navigator, and continues to launch normally to avoid a hard crash. The diagnostic therefore looks healthy at the surface even though the project tree is locked.

Three additional causes can produce the same observable behaviour and must be ruled out before deleting the file:

4. Diagnostic Workflow

Run the following sequence before applying the corrective action. Each step is non-destructive and can be executed on a production engineering station without affecting live controller projects.

1. Verify the file exists. Open an elevated command prompt and run dir "C:\Program Files\Siemens\Step7\u7umc\data\wrkbnch\UESPersi.dat" /A. On a fresh install the file is normally absent; its presence on a first-time install indicates a prior failed install or a Windows roaming profile that has copied it from another machine.
2. Check file ownership. From the same prompt run icacls "C:\Program Files\Siemens\Step7\u7umc\data\wrkbnch\UESPersi.dat". The file must be owned by the local Administrators group and grant SYSTEM:F and Administrators:F. If ownership shows TrustedInstaller or a domain account, SCOUT cannot rewrite it and the comparison fails silently.
3. Inspect the application event log. Open eventvwr.msc and filter for source = SIMOTION SCOUT and .NET Runtime. An entry like Exception code: 0xE0434352 in combination with Could not load file or assembly points to a corrupt .NET cache rather than a stale UESPersi.dat.
4. Confirm the SIMATIC Manager is the host. SCOUT cannot operate as a stand-alone process. The shell must be Step 7 SIMATIC Manager V5.4 SP5 or V5.5 SP4 (or TIA Portal V13+ for the TIA edition). Check Help → About inside SIMATIC Manager; an out-of-date shell will report the SCOUT version as unknown even when the DLLs are present.
5. Verify RAM and disk. Run wmic OS get FreePhysicalMemory,TotalVisibleMemorySize /Value and wmic logicaldisk get FreeSpace. SCOUT V4.x/V5.x requires at least 2 GB of physical memory and 4 GB of free disk space on the system drive for the working copies; less than that causes the same symptom because the registration routine aborts before completion.

5. Primary Solution: Clear the Workbench Cache

The corrective action that has been confirmed on multiple SIMOTION engineering stations is to delete the stale UESPersi.dat file and let SCOUT rebuild the cache on the next launch. The procedure is:

1. Close all open SIMATIC applications, including SIMATIC Manager, SCOUT, S7-PCT, SIZER, WinCC flexible, and the SIMOTION device trace tool. Confirm in Task Manager that the process S7WM.exe (the SIMATIC Manager workbench shell) is no longer running.
2. Open Windows Explorer and navigate to C:\Program Files\Siemens\Step7\u7umc\data\wrkbnch. If the host is 64-bit and SCOUT was installed in 32-bit mode, the path is C:\Program Files (x86)\Siemens\Step7\u7umc\data\wrkbnch.
3. Right-click UESPersi.dat and select Delete. If the file is not present, skip to step 5 — the system is already in a clean state.
4. Empty the Recycle Bin to prevent Windows Search from resurrecting a thumbnail/index of the file.
5. Launch SIMATIC Manager, then open SCOUT from the SIMOTION menu. SCOUT will recreate UESPersi.dat automatically. The Project Navigator should be enabled within 30 to 60 seconds of SCOUT finishing the workbench scan.

On Windows 7 and later, the file may be locked by the BITS service or the Superfetch component. Stop those services before the deletion:

net stop BITS
net stop sysmain
del /F "C:\Program Files (x86)\Siemens\Step7\u7umc\data\wrkbnch\UESPersi.dat"
net start BITS
net start sysmain

6. Secondary Solution: Address Software Conflicts

If deleting UESPersi.dat does not enable the Project Navigator, the next most common cause is a third-party process holding a write lock on the workbench files. Address each item in the order listed.

6.1 Google Desktop and similar indexers

Google Desktop, Copernic Desktop, and Windows Desktop Search open persistent handles to every file in Program Files so that the index stays current. When SCOUT attempts to rewrite UESPersi.dat, the write fails and the registration is aborted, leaving the Project Navigator disabled. Uninstall the indexer through Control Panel → Programs and Features, then reboot and re-run SCOUT.

6.2 SIZER co-installation

Siemens SIZER for SIMOTION / SINAMICS shares a number of COM components and runtime DLLs with SCOUT. When both are installed, the COM resolver can load SIZER's version of S7wnc.dll instead of SCOUT's, and the workbench registration silently fails. The supported configuration is to install SIZER first and SCOUT second; if SCOUT is already present, the SIZER installer must be removed and the workstation restarted before SCOUT is re-applied.

6.3 STEP 7 / WinCC flexible conflicts

SCOUT V4.3 / V4.4 require WinCC flexible 2008 SP2. SCOUT V5.0 / V5.1 require WinCC flexible 2008 SP3. SCOUT V5.2 and later require TIA Portal or WinCC flexible 2008 SP5. Mismatched patch levels have been observed to disable the Project Navigator while leaving every other SCOUT menu functional. Use the SIMOTION SCOUT V5.x operating instructions matrix (chapter 1.3, "Software requirements") to verify the exact required combination for the installed SCOUT version.

6.4 DCOM and firewall

On multi-engineer commissioning setups SCOUT uses DCOM to push the project to a remote PG. Windows Firewall and most corporate endpoint protection software block DCOM by default on Windows 7 / 10. The Project Navigator will not be disabled by this, but if SCOUT and STEP 7 are installed on a workstation joined to a domain with restricted DCOM, the Navigator will refuse to call up the online objects. The corrective action is documented in Siemens KB entry 109751469 (section "Distributed engineering → DCOM configuration").

7. Hardware and Performance Requirements

The minimum and recommended specifications for SCOUT V4.x and V5.x are:

8. Clean Re-installation Procedure

If the primary and secondary actions above do not restore the Project Navigator, perform a full clean re-install. This is the same procedure Siemens support engineers apply when a corrupt registry cache is suspected.

1. Uninstall in reverse order: WinCC flexible, SCOUT, SIMOTION IT, STEP 7, Microsoft .NET Framework, MSXML, Microsoft SQL Server 2005 Express (used by the SCOUT project archive). Use Control Panel → Programs and Features on Windows 7 / 10 or Add or Remove Programs on XP.
2. Delete the following directories manually (after backup of any local projects):

   rd /S /Q "C:\Program Files\Siemens\Step7"
   rd /S /Q "C:\Program Files (x86)\Siemens\Step7"
   rd /S /Q "C:\ProgramData\Siemens"
   rd /S /Q "%LOCALAPPDATA%\Siemens"
   rd /S /Q "%APPDATA%\Siemens"

3. Remove the residual registry keys with regedit:

   HKLM\SOFTWARE\Siemens\Automation
   HKLM\SOFTWARE\Wow6432Node\Siemens\Automation
   HKCR\CLSID\{SIMOTION workbench GUIDs}

   The full list of GUIDs is reproduced in SCOUT operating instructions 109751469, appendix C.
4. Reboot and confirm the system is clean by searching for Siemens in the registry. Only the Microsoft SQL Server 2005 Express entry should remain.
5. Install STEP 7 first, apply the latest Service Pack, install SCOUT second, then apply the SCOUT Hotfix (HF) referenced on the SIMOTION SCOUT product page.
6. Launch SCOUT and verify the Project Navigator is enabled before restoring any project from backup.

9. Verification

After applying the corrective action, validate that the workbench is fully functional. The following checks each exercise a different code path inside the SCOUT shell, so a pass on all five is strong evidence that the registration is healthy.

1. Project Navigator enabled. Open SIMATIC Manager with a SCOUT project selected, then choose SIMOTION → Project Navigator. The Navigator dialog must open; if it remains disabled, the cache has not been rebuilt correctly.
2. Hardware detection. From SCOUT, select Target system → Select target device → Browse. The connected SIMOTION controller (D410 / D425 / D435 / D445 / D455 / C230-2) must appear in the accessible nodes list with its firmware version and serial number.
3. Project download dry run. Right-click the SIMOTION device in the project tree and choose Download to target system → Test and Commissioning. SCOUT must build a consistent project image and report Download ready without prompting for a missing technology object.
4. Trace tool availability. Open Tools → Trace. Both the Servo trace and Function trace tabs must be selectable. If only the Function trace tab is present, the SCOUT device library has not been registered even though the shell itself is fine.
5. Help file resolution. Press F1 inside the Project Navigator. The SCOUT help index must resolve to the correct topic. A "Could not display the topic" message indicates that the help file path in the registry still points to the old install location.

10. Prevention and Best Practice

To minimise the chance of recurrence on engineering stations used for SIMOTION commissioning:

• Maintain a documented baseline image (Acronis, Symantec Ghost, or Veeam Agent) that includes STEP 7 + SCOUT at a known working patch level. The image must be built after at least one successful SCOUT launch so that the workbench cache is created in a clean state.
• Avoid the use of file-system indexers (Google Desktop, Copernic, Everything) on SCOUT workstations. If an indexer is required for project search, scope it to user data folders only and exclude Program Files\Siemens.
• Apply SCOUT Hotfixes as soon as they are released on the SIMOTION SCOUT product page. HF collections typically address the UESPersi.dat write-failure modes that produce the symptom described in this article.
• Keep a copy of the engineering station's wrkbnch directory in a controlled location so that the corrective action (delete the file, relaunch SCOUT) can be performed on remote sites without re-installing the full software stack.

11. Related Symptoms and Cross-References

The same root cause can manifest in adjacent ways. The table below maps the symptom to the corrective action.

12. Frequently Asked Questions