Resolving STEP 7 V5.5 SIMATIC Manager Browse Dialog Hang

Problem Definition

The File > Open > Browse dialog in SIMATIC Manager (STEP 7 V5.5) enters a "Not Responding" state when the user clicks the Browse button on the Open Project dialog. The window title bar gains the (Not Responding) suffix after roughly 10–25 seconds, the UI grays out, and the only available recovery is a forced termination through Task Manager (taskkill /F /IM S7WEBSPX.EXE or End Process on S7WEBSPX.EXE / S7MANAGR.EXE).

This symptom is specific to the Browse path under File > Open > Browse (the project selection dialog that exposes the standard Windows shell browser). Typing a fully qualified UNC path (e.g., \\SERVER\PROJECTS\PLANT_A.S7P) directly into the Name field continues to work in many cases, even when the Browse button hangs. That distinction is the most important diagnostic clue in the field: it confirms the failure lies in the shell enumeration / project-tree caching layer, not in the STEP 7 project loader itself.

Affected Versions and Environment Matrix

Root Cause Analysis

Across the field, the "Browse not responding" symptom maps to one of seven underlying root causes. Step through them in this order; the first match is almost always the answer.

Cause 1 – Aborted Open of a Network Project (most common)

STEP 7 V5.5 caches an open-project handle to the last UNC path in the user profile (%APPDATA%\SIEMENS\STEP7\S7Proj\LASTPRJ.INI and registry HKCU\Software\Siemens\STEP7\Settings\LastProject). If the engineering station is closed, suspended, or disconnected from the network while a project on a UNC share is still loaded, the cached handle becomes stale. On the next launch, the Browse dialog attempts to enumerate the unavailable UNC root, blocks on a NetrDfsGetClientInfo / WaitForSingleObject call, and the dialog thread never returns.

Evidence: Open regedit and inspect HKCU\Software\Siemens\STEP7\Settings. A path that no longer exists (or contains a removed server name) confirms this cause.

Cause 2 – Windows Shell Extension Conflict

The Browse dialog uses the Windows ShellBrowser control. Third-party shell extensions (Dropbox, OneDrive, Google Drive, antivirus on-access scanners, network sync agents, TortoiseSVN overlay handlers) hook into IShellFolder enumeration. STEP 7 V5.5 runs as a 32-bit process even on x64 Windows, so it loads extensions from HKLM\SOFTWARE\Wow6432Node\...\Approved Shell Extensions. A misbehaving extension blocks the enumeration call indefinitely.

Evidence: Process Monitor (ProcMon) shows the dialog thread stuck in IRegistryItem::GetDisplayNameOf against a virtual namespace (CLSID\{{E88DCCE0-B7B3-11D1-A9F0-00AA0060FA31}}) belonging to a cloud sync provider.

Cause 3 – SMB1 Disabled on Target Server

STEP 7 V5.5 project files rely on SMB1 / NT LAN Manager for UNC enumeration of legacy file shares. Windows 10 1709+ and Server 2019 disable SMB1 by default. When the Browse dialog attempts NetShareEnum against an SMB2/3-only share, the API call does not return cleanly inside the dialog's 30-second wait window.

Evidence: Get-SmbConnection on the engineering station shows only SMB3 dialects; Get-SmbServerConfiguration | Select EnableSMB1Protocol on the file server returns False.

Cause 4 – Missing or Corrupted Visual C++ Runtime

SIMATIC Manager depends on the Visual C++ 2005 SP1 and 2008 SP1 redistributables (msvcr80.dll, msvcp80.dll, msvcr90.dll, msvcp90.dll). The custom dialog framework uses these for path normalization. A broken redistributable install (commonly seen after a Windows 10 feature update replaces msvcr*.dll with newer incompatible versions) produces a deadlock during IFileDialog::SetFolder.

Evidence: Dependency Walker (depends.exe) shows msvcr80.dll loaded with LATEST binding and a version mismatch warning.

Cause 5 – User Profile Corruption

STEP 7 V5.5 stores per-user dialog state, recent project list, MRU, and column widths in %APPDATA%\SIEMENS and %LOCALAPPDATA%\SIEMENS. A corrupted profile (interrupted logoff, mandatory profile reset, redirected profile issues) leaves the Browse dialog stuck loading step7.mru / prjtree.ini.

Evidence: Renaming %APPDATA%\SIEMENS to %APPDATA%\SIEMENS.OLD and restarting SIMATIC Manager makes the Browse button responsive within 5 seconds.

Cause 6 – Antivirus Real-Time File Scanning

Symantec Endpoint Protection, McAfee ENS, Trend Micro Apex One, and CrowdStrike Falcon (with on-access scan enabled for ZIP/PKL/STL) intercept every file enumeration call inside the Browse dialog. Each IEnumIDList::Next triggers a scan, and a slow signature update path can push enumeration past the 30-second GDI timeout.

Evidence: ProcMon shows a flood of CreateFile + FILE_SHARE_READ attempts on *.tmp patterns created by the shell browser, each followed by a 2–4 second FASTIO_NETWORK_QUERY_OPEN response from the AV minifilter.

Cause 7 – Active Project Lock from Another Session

STEP 7 V5.5 uses a cooperative file lock (~$$$.LOCK hidden file inside the project directory) to prevent concurrent editing. If a prior session terminated abnormally, the lock file persists with the original owner SID. The Browse dialog queries the lock state before listing projects, and on a stale SID lookup the call hangs.

Evidence: icacls "C:\Projects\Plant_A\~$$$.LOCK" returns a non-resolvable SID (S-1-5-21-...-500 of a deleted account).

Pre-Diagnostic Snapshot

Before applying any fix, capture a baseline so the change is reversible and measurable.

1. Record exact build: Help > About in SIMATIC Manager; capture the full string (e.g., STEP 7 V5.5 + SP4 + HF11 (K5.5.4.0)).
2. Capture OS build: winver; note edition, build number, and 32 vs 64-bit.
3. List recent project paths: Export HKCU\Software\Siemens\STEP7 via reg export HKCU\Software\Siemens\STEP7 step7.reg.
4. Snapshot the user profile: robocopy "%APPDATA%\SIEMENS" "D:\BACKUP\SIEMENS_%date%" /E /ZB.
5. Capture a ProcMon trace filtered to S7WEBSPX.EXE and S7MANAGR.EXE for 60 seconds while reproducing the Browse click. Save as .PML for post-mortem.

Solution Path A – Resolve Stale Network Project Handle

Apply this first; it solves the majority of incidents on the factory floor.

1. Close SIMATIC Manager completely. Verify in Task Manager that S7WEBSPX.EXE, S7MANAGR.EXE, S7OTBLEDX.EXE, CCAGENT.EXE are not running. Force-kill any stragglers with taskkill /F /IM S7WEBSPX.EXE.
2. Reconnect the engineering station to the same network where the last project was hosted, or remap the drive letter using net use Z: \\FILESERVER\PROJECTS /user:DOMAIN\user.
3. Open File > Open directly (no Browse) and load the original project. Save, then close SIMATIC Manager cleanly via File > Exit. This clears the cached handle.
4. If the original server is permanently unavailable, edit HKCU\Software\Siemens\STEP7\Settings and remove (or correct) the LastProject value. Log off and back on.
5. Launch SIMATIC Manager and confirm Browse responds.

Solution Path B – Repair the STEP 7 Installation

Use the original installation medium (CD or ISO). The repair install replaces corrupted S7*.DLL files, COM registrations, and shell extension entries without touching project data.

1. Insert the STEP 7 V5.5 DVD (or mount the ISO). If using a service pack DVD, mount the latest SP4 + HF11 image.
2. Run Setup.exe as Administrator (right-click > Run as administrator).
3. Select the language and accept the license. The installer detects the existing installation and presents three options: Install, Modify, Repair.
4. Choose Repair, leave all components selected, and proceed.
5. Reboot when prompted. Apply any post-repair service pack or hotfix that was previously installed.
6. Verify the Browse dialog.

Solution Path C – Correct Windows Operating System Compatibility

Refer to the official Siemens compatibility matrix, maintained as Entry ID 64847781 in the Siemens Industry Online Support portal. Confirm the running OS is on the approved list for the installed STEP 7 version.

If the OS is not on the approved list, apply the highest installed service pack plus hotfix and configure:

1. Disable UAC: secpol.msc > Local Policies > Security Options > User Account Control: Run all administrators in Admin Approval Mode = Disabled. Reboot.
2. Run SIMATIC Manager elevated: Properties > Compatibility > Run this program as administrator.
3. Compatibility shim (Win10/11): Set compatibility to Windows 7 and check Disable display scaling on high DPI settings.
4. Disable FIPS: secpol.msc > Security Settings > Local Policies > Security Options > System cryptography: Use FIPS compliant algorithms = Disabled.

Solution Path D – Reinstall the VC++ Runtime Stack

1. Download vcredist_x86_VC2005_SP1.exe, vcredist_x86_VC2008_SP1.exe, and vcredist_x86_VC2010_SP1.exe from the Microsoft Visual Studio Redistributable archive.
2. Uninstall any existing Microsoft Visual C++ 2005/2008/2010 Redistributable entries via Programs and Features.
3. Reboot.
4. Install the three redistributables in ascending version order (2005, then 2008, then 2010).
5. Reboot. Launch SIMATIC Manager and test Browse.

Solution Path E – Rebuild the User Profile Cache

1. Close SIMATIC Manager.
2. Rename the profile directories (do not delete; engineers need to roll back):

   ren "%APPDATA%\SIEMENS" "%APPDATA%\SIEMENS.OLD"
   ren "%LOCALAPPDATA%\SIEMENS" "%LOCALAPPDATA%\SIEMENS.OLD"

3. Launch SIMATIC Manager. The directories are recreated with default MRU, column widths, and recent paths.
4. Test Browse. If functional, copy any needed custom column layouts or recent project shortcuts from the .OLD directories.
5. Delete the .OLD directories after one week of stable operation.

Solution Path F – Eliminate Shell Extension Interference

1. Download ShellExView (NirSoft) or Autoruns (Microsoft Sysinternals).
2. Disable all non-Microsoft shell extensions temporarily. Restart Explorer (taskkill /F /IM explorer.exe & start explorer.exe).
3. Test the Browse dialog.
4. Re-enable extensions in batches of 5–10, testing after each batch, until the failing extension is isolated.
5. Permanently disable the offending extension (or update it to a STEP 7 V5.5-compatible version). Common offenders in 2024–2025: Box Drive v3, OneDrive 24.x, Dropbox v200+, Evernote 10, ESET Shell Extension.

Solution Path G – Clear Stale Project Locks

1. Locate the project root directory (e.g., D:\Projects\Plant_A\).
2. Show hidden files in Explorer (View > Show > Hidden items).
3. Identify the lock file (~$$$.LOCK or files matching *. with 0 bytes and timestamps older than the current session).
4. Verify ownership with icacls "D:\Projects\Plant_A\~$$$.LOCK". If the SID is unknown, take ownership and delete.
5. If multiple engineering stations share the project directory, coordinate the lock removal via change management. Never delete a lock from a session you cannot prove is dead.

Verification Checklist

Run these checks in order. Each must pass before moving to the next.

1. Browse dialog responsiveness: Click File > Open > Browse. The dialog must render the project tree in under 5 seconds with no (Not Responding) suffix. Verify against both a local and a UNC path.
2. Direct UNC entry: Type \\FILESERVER\PROJECTS\PLANT_A.S7P into the Name field and confirm Open loads the project.
3. Recent projects list: File > Open must populate the Recent projects pane from prjtree.ini.
4. Save / Save As: Modify a comment in a block, save the project, and confirm the dialog closes promptly.
5. Project archive: File > Archive must complete and write a valid .ARJ archive.
6. Online connection: PLC > Download to Target must enumerate accessible stations via the Browse dialog without hang.
7. SIMATIC Manager restart: Close and reopen; Browse must remain responsive on the second launch.

Prevention and Best Practices

• Never close the laptop lid while a STEP 7 project is open on a UNC share. Suspending with an open network handle is the single largest contributor to the symptom. Train all engineers: Close Project > Exit SIMATIC Manager > Sleep.
• Always operate from a local copy. Mirror UNC projects to C:\S7PROJ\ using robocopy /MIR before editing. STEP 7 V5.5 performance and stability on local NTFS is materially better.
• Maintain a service pack baseline. Keep STEP 7 at V5.5 SP4 + HF11 (or the highest available hotfix for your OS). The hotfixes after SP3 contain specific Browse dialog stability fixes.
• Document the engineering station image. Capture a Sysprep / Acronis / Veeam image after a clean install and verify Browse. Re-image any new station before commissioning rather than installing from scratch.
• Audit shell extensions annually. New versions of cloud sync agents routinely introduce conflicts. Schedule a quarterly shell extension review.
• Reserve SMB1 only when unavoidable. Where STEP 7 V5.5 must reach a legacy file server, isolate the SMB1 negotiation on that subnet and document the exception.
• Maintain a known-good ProcMon baseline. Capture a working ProcMon trace from a healthy station. Diff future traces against this baseline to identify new extension or driver interference.

Related Siemens Documentation

The following Siemens Industry Online Support entries are relevant to this troubleshooting path:

• Which version of STEP 7 is compatible with which version of Microsoft Windows operating system? (Entry ID 64847781) – OS compatibility matrix.
• Working with STEP 7 projects on network drives (Entry ID 51412188) – UNC handling best practices.
• Information about STEP 7 V5.5 SP1 (Entry ID 109476994) – Service pack contents.
• How do you perform a repair installation of STEP 7? (Entry ID 109750034) – Repair install procedure.