Step 7 V5.5 SP1: Troubleshooting Project Open Failures

1. Problem Description and Symptoms

A STEP 7 V5.5 SP1 project refuses to open in the SIMATIC Manager: clicking the project file or folder in the Open dialog immediately deselects the entry and closes the folder window without generating an error message, log entry, or warning dialog. The previous revision of the same project opens normally on the same workstation. The user has already verified:

• Language settings of the STEP 7 installation (multi-language installer package)
• CPU support inside the local Hardware Catalog
• File attributes after copying from CD (read-only flag cleared)

This silent-failure pattern is characteristic of project-validation routines that the SIMATIC Manager performs during Open: when one or more required components are missing from the workstation, when a project-database integrity check fails, or when mandatory metadata cannot be read, the Open function returns the focus to the dialog without surfacing an error. Recovering the project therefore requires validating every dependency before STEP 7 is allowed to complete the open transaction. The fault is typically recorded in the Windows Event Viewer under Application > S7HCOM / S7HK sources; enabling the Event Viewer log is the fastest way to capture a stack trace when the silent-fail recurs. Reference: Siemens Industry Online Support.

2. Root-Cause Matrix

3. Root Cause 1 — Missing S7-SCL Optional Package

S7-SCL (Structured Control Language) is the optional high-level language add-on for STEP 7 V5.x. It is licensed separately and installed as an add-on. If a project contains SCL source files (*.scl) or if any FC, FB, DB, or OB was last generated by the SCL compiler, the SIMATIC Manager will attempt to load the SCL editor and the SCL compiler during the Open transaction. Without SCL installed, this load fails inside the Open routine before the project is fully realized, producing the silent-deselect symptom described above. The matching optional package for STEP 7 V5.5 SP1 is S7-SCL V5.3 SP1; the license key (a K5 key transferred by the Automation License Manager) is required at runtime. Without the license key, SCL will install but the SCL sources will open read-only.

Diagnostic sequence:

1. In Windows Explorer, browse the project folder and look for a Sources subfolder. If *.scl files exist, SCL is required.
2. In the SIMATIC Manager, open the Blocks container of the previous (working) revision. Right-click any block → Object Properties. If the Created by field or block header references an SCL compiler string, SCL is required.
3. Open Help > About on a workstation known to have opened the project and confirm the Installed software list shows S7-SCL V5.3 SP1.

Resolution:

• Preferred: Install S7-SCL V5.3 SP1 on the local workstation. Contact the machine builder for a licensed copy, or
• Alternative: Ask the source engineer to export only the compiled blocks (no SCL sources) using the SCL compiler's Compile > Generate block and then File > Save As with the Sources folder excluded. Compiled blocks load into standard STEP 7 without SCL.

4. Root Cause 2 — STEP 7 Version / SP / Hotfix Mismatch

STEP 7 V5.5 follows a strict version chain: V5.5 > V5.5 + HFx > V5.5 SP1 > V5.5 SP1 + HFx. The SIMATIC Manager allows opening a project with the same version or any newer version, but never with an older version. A project saved on V5.5 SP2 + HF7 cannot be opened on V5.5 SP1. The Open routine returns silently rather than displaying a version-mismatch error, which is the symptom reported.

Diagnostic sequence:

1. Open the project on the source workstation: Help > About. Note the exact Product version string, e.g. V5.5 + SP1 + HF1.
2. On the local workstation: Help > About. Confirm whether the local version is identical, older, or missing a hotfix.
3. Cross-check the on-disk timestamps of *.s7p (compressed project) or the top-level project folder: an on-disk modification time later than the local install date is a strong indicator of a newer source.

Resolution:

• Install the missing Service Pack and/or Hotfix on the local machine. STEP 7 V5.5 SP1 is delivered as the cumulative STEP 7 V5.5 SP1 DVD plus optional hotfixes; the SP1 DVD is required before any HF can be installed.
• If upgrading is not possible, ask the source engineer to perform File > Save As on the older STEP 7 version explicitly, or to uninstall the hotfix and re-save on the older version.

5. Root Cause 3 — Hardware Catalog Mismatch

The HW Config catalog contains the device master records (DMR) for every Siemens and approved third-party module STEP 7 knows about. The catalog is updated separately from the core installer via HW Update (HWE) packages. When a project references a CPU, IM, FM, CP, or IO module that the local catalog does not contain, the project is considered incomplete by STEP 7 and the Open function refuses the project.

Diagnostic sequence:

1. Open the previous, working version of the same project on the local workstation. Note the CPU order number (for example, 6ES7 315-2EH14-0AB0) and the module list under HW Config > Station > Catalog.
2. Compare against the new project. If a module order number is not present in the local catalog, that is the likely cause.
3. Open HW Config > Options > Install HW Updates. The currently installed update level is displayed in the dialog. If the project was saved with a newer HW update level, install the appropriate update package.

Resolution:

• Open the local catalog, right-click the station, and add the missing module from the catalog only if it is already installed. If not, install the HW Update package that contains the module from Siemens Industry Online Support.
• If the CPU family is not supported at all (for example, an S7-1500 saved into a STEP 7 V5.5 project — STEP 7 V5.5 does not support S7-1500), the project must be reopened in the matching engineering tool (TIA Portal V13+).

6. Root Cause 4 — Project Corruption (Uncompressed Handoff)

STEP 7 V5.5 supports two project representations: a single compressed archive (typically *.s7p, or the standard File > Archive output as *.zip or *.arj) and an uncompressed folder tree. The compressed form is the only reliable form for handoff because it guarantees that the multi-file internal database is closed and consistent. When a project is sent as a folder copied directly to CD, the following can occur:

• The internal database files (residing inside the S7Proj tree) can be left in an open, inconsistent state because the original Close Project was bypassed.
• CD burning may truncate or skip zero-length system files.
• Hidden / system files required by the project may not be included in the burn set.
• Read-only attributes are inherited from the CD, and the inverse — write-protected files inside the project — is also possible.

Diagnostic sequence:

1. Open a Command Prompt at the project root and run dir /a /s. Compare the count of files and total size to a known-good project of similar scope. A project that has even 20% fewer files is suspicious.
2. Look for zero-byte files inside the S7Proj\<project>\<station>\<cpu>\S7Program sub-tree. Any *.sdb, *.s7p, or *.s7l at 0 bytes is fatal.
3. Look for the file Version.project and station-level pdm files. These are the project-database manifests. If their timestamp is later than their parent folder's timestamp, the project was not closed cleanly.

Resolution:

• Reorganize: File > Reorganize rebuilds the project database. If the project is partially corrupted, Reorganize often succeeds where Open fails. Open the project as a folder (not a file) and run Reorganize.
• Retrieve: If you have any archive (even a partial zip), use File > Retrieve to perform a controlled extraction. The Retrieve function restores the proper folder structure including hidden files.
• Fresh handoff: When all else fails, ask the source engineer to perform File > Archive (this closes the project cleanly and produces a self-contained archive) and to send that archive on a fresh medium.

7. Root Cause 5 — File Attributes and NTFS Permissions

When a project is copied from a CD or USB stick that used a non-NTFS-aware transfer, the read-only attribute is set on every file. STEP 7 writes lock files and metadata during Open; if even one file is read-only, the project open can fail without surfacing the reason. NTFS-level denial of write permission produces the same symptom, especially when the project sits under C:\Program Files (x86)\Siemens\Automation\... where UAC elevation and Program Files protection are in force.

Diagnostic sequence:

1. Open Command Prompt at the project root and run attrib /S /D -r *.* to clear read-only attributes recursively.
2. Right-click the project folder → Properties > Security. Confirm the user has Modify, Read & Execute, and Write on the folder, subfolders, and files.
3. Check for NTFS Encrypt flags: cipher /s:C:\projects /d removes encryption from a folder tree if the user has rights.

Resolution:

• Run attrib -r -h -s "C:\projects\<project>\*.*" /S /D as administrator.
• If the project resides in C:\Program Files (x86)\Siemens\Automation\... or another protected location, move it to a user-owned directory (e.g. D:\Projects\<project>) and re-open.
• Disable any anti-virus that is silently locking files; add the project root to the AV exclusion list.

8. Root Cause 6 — STEP 7 Language / .dll Integrity

STEP 7 V5.5 is shipped with separate language components. The language files (and a number of core .dll files in ...\Siemens\Automation\S7bin, including s7hcom_x.dll, s7hkcom.dll, and the station-interface libraries) are loaded at SIMATIC Manager startup. A related failure — Step 7 language file failed to open — has been documented when third-party OPC-DA bridges and tag-import tools attempt to import S7 tags through the STEP 7 language interface. While that specific error is observed on the OPC-DA bridge side, the underlying cause is the same: an S7 language file is not in the expected location, is locked by another process, or is corrupted.

Diagnostic sequence:

1. Open Start > Control Panel > Programs > Programs and Features. Confirm SIMATIC STEP 7 V5.5 is installed with the language pack used by the source engineer (e.g. English, German).
2. Verify the directory C:\Program Files (x86)\Siemens\Automation\S7bin contains s7hcom_x.dll and that the timestamp matches the install date.
3. Run STEP 7 > AuthorsW > Set PG/PC Interface and confirm the interface assignment is reachable.

Resolution:

• Reinstall the STEP 7 language component from the original DVD: Control Panel > Programs > STEP 7 > Change > Modify > Language.
• Exclude the entire C:\Program Files (x86)\Siemens\Automation tree from any real-time anti-virus scanner that may be opening files exclusively.
• Re-register the S7HCOM and S7HK DCOM servers: open an elevated command prompt, navigate to S7bin, and run regsvr32 s7hcom_x.dll followed by regsvr32 s7hkcom.dll.

9. STEP 7 V5.5 SP1 Project File Structure Reference

A STEP 7 V5.5 SP1 project, when stored as an uncompressed folder, has the following canonical layout:

<project_root>\
  Global\                        (cross-station data)
  <Station_1>\
    HwConfig\                    (HW Config data)
    S7Progs\                     (CPU program data)
      Blocks\                    (compiled blocks: OB, FB, FC, DB, SFB, SFC, UDT)
      Sources\                   (SCL / STL / S7-Graph source files)
      Symbols\                   (symbol table, optional)
      S7P<CPU>_<FS>             (offline/online system data)
  <Station_2>\
  ...
  s7asrcom\                      (offline/online compare data)
  Version.project                (STEP 7 version stamp written on save)
  <project>.s7p                  (compressed master, optional)

Each subfolder contains one or more *.pdm files (project-database manifests) and matching *.s7l lock files. When the Open routine encounters an inconsistency in any of these .pdm files — typically a missing lock file or a partially flushed manifest — the open transaction is aborted. The Reorganize function rebuilds the manifests in place; the Retrieve function extracts an archive into a fresh, consistent tree.

10. Inline Flowchart — Recovery Decision Tree

11. Step-by-Step Recovery Procedure

Execute the steps in the order shown. Stop at the first step that succeeds.

1. Confirm the open attempt is silent-fail. From the SIMATIC Manager menu, select File > Open. Confirm the selection deselects and the folder closes without a dialog. Check the Windows Event Viewer under Application > S7HCOM for a recent entry.
2. Clear file attributes. From a Command Prompt at the project root: attrib -r -h -s *.* /S /D. Retry the open.
3. Check SCL dependency. Browse the project's Sources folder. If any *.scl file is present, install S7-SCL V5.3 SP1 or obtain an SCL-free export.
4. Compare HW catalog level. Open the previous (working) revision. In HW Config > Options > Install HW Updates, note the installed HW update level. If the new project uses modules that require a higher HW update, install the update from Siemens support.
5. Compare STEP 7 version. On both the source and local workstations, run Help > About. The local version must be equal to or higher than the source. Upgrade local if required.
6. Reorganize. From the SIMATIC Manager, File > Reorganize. The dialog asks to back up the project first — accept. Reorganize rebuilds the project database.
7. Retrieve from any archive present. If a *.zip or *.arj file is on the medium, use File > Retrieve to perform a controlled extraction to a fresh directory. Open the retrieved project.
8. Request a clean archive. If all of the above fail, request that the source engineer perform File > Archive, attach the resulting archive to a fresh CD/USB, and re-send.

12. Verification Steps

After the project opens successfully, perform the following to confirm that it is fully usable and not in a partial state:

1. Project navigation: expand SIMATIC 300 Station or SIMATIC 400 Station → CPU → S7 Program → Blocks. Confirm all OBs, FBs, FCs, DBs, SFBs, and SFCs are present and have non-zero file size.
2. HW Config consistency: open HW Config. The station should display the configured modules without yellow exclamation marks. If any module displays a yellow icon, the catalog is still missing a required entry.
3. Block consistency: right-click the Blocks folder → Check Block Consistency. All blocks should report OK. Blocks with Time stamp conflict indicate a re-compile is required.
4. Compile: Program > Compile All (or Program > Compile and Download Objects). The compile should finish without errors. Address any SF (syntax fault) reports in the output window.
5. Online test (only if hardware is reachable): PLC > Online > Accessible Nodes. Confirm the CPU is visible and the online block list matches the offline block list.

13. Handoff Best Practices

• Always archive. The source engineer must use File > Archive (not Copy). The resulting archive is self-consistent and includes hidden files.
• Document the environment. The handoff email or transmittal should list: STEP 7 version + SP + HF, S7-SCL presence and version, S7-GRAPH presence and version, HW catalog update level, and the target CPU order number.
• Match the receiver. The receiver should run the same or higher STEP 7 SP, with the same optional packages installed (SCL, GRAPH, HiGraph, CFC).
• Use a non-CD medium. CD media enforce the read-only attribute and complicate permission. A USB stick or SFTP/FTP share preserves attributes accurately.
• Test the archive. Before sending, the source engineer should File > Retrieve the archive into a temporary directory and confirm the retrieved project opens. This round-trip is the strongest guarantee of integrity.
• Anti-virus exclusion. Add %ProgramFiles(x86)%\Siemens\Automation and the project root to the AV exclusion list on every workstation that opens the project.

14. Edge Cases and Field Notes

• OneDrive / SharePoint sync: STEP 7 V5.5 projects are not designed for cloud-sync. Sync clients hold files open exclusively during upload, which triggers silent-fail on Open. Always keep STEP 7 V5.5 projects on local NTFS storage.
• Roaming user profiles: if the project is stored under %USERPROFILE%\Documents on a domain-joined workstation with a roaming profile, the project may be partially read while sync is in progress. Place the project on a fixed local drive.
• Symbol table Unicode: STEP 7 V5.5 with the English language pack is generally UTF-8 tolerant, but if a symbol contains characters outside the ANSI range, the block open can fail. Replace the symbols with ASCII equivalents and re-save.
• Long path names: STEP 7 V5.5 has a path-length limit of approximately 256 characters (Windows MAX_PATH). Move the project closer to the drive root if any file path approaches this limit.
• DCOM permissions: STEP 7 uses DCOM for the S7HCOM and S7HK servers. If the local firewall or DCOM launch permissions are misconfigured, the language file load can fail at SIMATIC Manager startup, presenting as an Open failure on any project.

15. Quick Diagnostic Command Set

REM Step 1: clear all attributes recursively
attrib -r -h -s "D:\Projects\MyMachine\*.*" /S /D

REM Step 2: list zero-byte files (fatal)
forfiles /P "D:\Projects\MyMachine" /S /M *.* /C "cmd /c if @fsize EQU 0 echo @path"

REM Step 3: count files vs. baseline (compare to known-good project)
dir /S /A "D:\Projects\MyMachine" | find "File(s)"

REM Step 4: confirm STEP 7 install path
where /R "C:\Program Files (x86)\Siemens\Automation" s7hcom_x.dll

REM Step 5: re-register STEP 7 DCOM servers
cd /D "C:\Program Files (x86)\Siemens\Automation\S7bin"
regsvr32 s7hcom_x.dll
regsvr32 s7hkcom.dll

16. Related Errors and Cross-References

• Step 7 language file failed to open — the same root-cause family as the silent-deselect failure, observed when OPC-DA bridges (KEPware, Simatic Net) attempt to import S7 tags. See Siemens Industry Online Support entries for S7HCOM and S7HK.
• Block has time stamp conflict — typically follows a successful Open that has been followed by an out-of-date online connection. Resolve by Program > Compile All and download.
• The system cannot find the file specified on SIMATIC Manager startup — language file missing; reinstall the language component.
• Project is read-only dialog — the symptom when the attribute issue is partial (some files writable, others not). Run the attribute-clearing command set in §15.

17. Specifications — STEP 7 V5.5 SP1 vs. Common Variants

Open the project's Version.project file in a text editor to confirm the exact STEP 7 version it was last saved with. The first line contains a string such as V5.5.1.0 (V5.5 SP1) or V5.5.4.0 (V5.5 SP4).

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