Fixing SIMATIC Manager Cross-Reference Errors After Reinstall

Problem Overview

After a clean uninstall/reinstall of SIMATIC Manager performed to recover from a missing S7TBROWX.dll runtime module, STEP 7 V5.4 SP2 may begin failing all cross-reference navigation in a previously working S7-300/S7-400 project. Two discrete error dialogs appear depending on the navigation path chosen:

• Options → Cross-Reference: "Internal error: Unable to set up the connection between the two objects".
• Right-click → Go To Location: "Unable to find the reference data required for execution.".

Both messages indicate that the per-project reference database is no longer aligned with the offline blocks and symbols. The most common root cause is project-level database corruption introduced by an interrupted upgrade, antivirus quarantine of .sec files, or a partial SIMATIC Manager reinstall that strips the cross-reference subsystem state without rebuilding it. The canonical field remedy, validated against STEP 7 V5.4 SP2, is to open the affected project and use File → Save As with the "with reorganization (slow)" option. This forces STEP 7 to rebuild the internal database tables (including the cross-reference cache) in a single pass.

Affected Environment

The fact that newly created projects cross-reference normally while the original project fails localizes the fault to the project files themselves rather than the SIMATIC Manager binaries. After a clean reinstall, the tool binaries are healthy, but the previous project's reference data was not migrated forward and is now unreadable.

Root Cause Analysis

SIMATIC Manager stores cross-reference data in two coordinated layers:

1. Project shell database — managed by the S7HCOMX and S7HSTAED services inside the project tree. This layer tracks block/symbol relationships and is rebuilt on demand.
2. Reference object container — the folder hierarchy under <project>\oms\maps\... plus the .sec / .srs files in the project root that cache operand occurrences.

The S7TBROWX.dll shipped with SIMATIC Manager exposes the OLE automation entry points SIMATICRefDataLib and IS7RefData consumed by the cross-reference and "Go To Location" menus. When this module is missing, deleted, or version-mismatched against the project's saved S7.TEA shell, the tool throws either of the two errors cited above.

Typical Corruption Vectors

Project Shell Structure

<project_name>\
├── <project_name>.s7p      → master project marker
│
└── oms\                     → offline management station data
    └── *.sec, *.srs            → reference cache files
Global\
├── Symbols\                  → symbol table (offline)
└── Language\
<station>\
└── CPU\
    └── S7 Program\
        ├── Blocks\              → offline block container
        └── Sources\             → STL/SCL sources

Solution A: Slow Project Reorganization (Primary)

This is the canonical field remedy and was validated against STEP 7 V5.4 SP2 in the source case.

1. Open the affected project in SIMATIC Manager.
2. Select the project root node and choose File → Save As.
3. Enable "with reorganization (slow)" in the Save As dialog.
4. Provide a new project name or overwrite the existing project. Confirm any prompt about closing the project.
5. Wait for the copy/reorganization to complete. A 5–10 MB project typically takes 30–90 s; multi-project setups with many libraries may take several minutes.
6. Open the new (or freshly reorganized) project and run Options → Cross-Reference → Display.

Solution B: S7TBROWX.dll Recovery

If the original condition (missing S7TBROWX.dll) has recurred, verify the file's presence, version, and registration before assuming project corruption is the sole cause.

Step 1 — Locate the Binary

• Default 32-bit install path: C:\Program Files\Siemens\Automation\SIMATIC Manager\Bin\S7TBROWX.dll
• For 32-bit STEP 7 on 64-bit Windows: C:\Program Files (x86)\Siemens\Automation\SIMATIC Manager\Bin\S7TBROWX.dll
• Typical size for V5.4 SP2: ~163,000 bytes (build 5.4.2.0 / 5.4.2.4)
• SHA-256 mismatch against an unaltered installation is a sign of tampering; reinstall from the original SP2 media.

Step 2 — Re-register the COM Object

1. Open an elevated command prompt (Run as Administrator).
2. From the directory containing S7TBROWX.dll, execute:

   regsvr32 /u S7TBROWX.dll
   regsvr32 /i S7TBROWX.dll

3. Confirm the DllRegisterServer / DllInstall succeeded message.

Step 3 — Repair the SIMATIC Manager Install

1. Open Control Panel → Programs and Features (Windows XP: Add/Remove Programs).
2. Select Siemens Automation SIMATIC → STEP 7, then click Change/Repair.
3. Choose Repair Installation and complete the wizard. Accept the prompt to re-register all OLE automation components — this rebuilds the CLSID entries for S7TBROWX.dll and the dependent libraries (S7WSDKAX.dll, W95S7COM.dll).

Additional installation guidance and licensing documentation are available via Siemens Industry Online Support.

Solution C: Manual Reference Data Rebuild

If Solution A still fails (typical on multi-project installations or when the source project is read-only or on read-only media), force a manual reference-data rebuild.

1. Close the project in SIMATIC Manager.
2. Open Windows Explorer and navigate to <project_root>\oms.
3. Locate all .sec and .srs files. Move them to a backup folder (do not permanently delete — they may be needed if the rebuild fails).
4. Re-open the project. SIMATIC Manager detects the missing reference cache and prompts to recompile.
5. Confirm the recompile. All offline blocks will be re-parsed; expect increased editor open time on the first cycle. A 200-block project usually recompiles in 60–120 s.
6. Validate by opening Options → Reference Data → Display.

Advanced Diagnostics: Registry and DCOM Integrity

For recurring failures across multiple projects, an integrity check at the registry and DCOM layer is required. Begin by capturing a snapshot of the registry as a baseline so each modification can be rolled back if necessary.

Registry Path Checks

DCOM and Permissions

• Open dcomcnfg → Component Services → Computers → My Computer → DCOM Config.
• Locate the entry SIMATIC Manager References; right-click → Properties → Security.
• Confirm Launch and Activation Permissions include the user running STEP 7. Service-account deployments must add the appropriate identity explicitly.
• Verify Access Permissions allow both Local Launch and Remote Launch for the user; without these, the cross-reference subsystem cannot register the in-process server.

Diagnostic Decision Flow

Verification and Test Procedure

After any of the solutions above, perform the following validation sequence to confirm the cross-reference subsystem is fully functional:

1. Cross-reference matrix: In SIMATIC Manager, select the S7 Program or block folder, then Options → Cross-Reference → Display. The matrix must open without error. Filter by operand type (MW, DB, I, Q) and confirm the row counts match the project size.
2. Go To Location: In an open LAD/FBD/STL block, right-click any operand (e.g., DB10.DBX0.0, M 4.0, I 0.0) and select Go To Location. The Where Used dialog must populate with all references.
3. Program identifier check: Options → Reference Data → Display. Confirm the program structure window opens and shows the assignment list, cross-reference, and program structure tabs.
4. Online reference data (optional): If a live PG/PC interface connection exists, PLC → Reference Data → Display must succeed without COM exceptions.
5. Project compact follow-up: File → Save As → with reorganization (slow) a second time should be near-instantaneous, confirming the cache is no longer being rebuilt.
6. Symbol table consistency: Options → Symbol Table → Consistency Check must report zero errors across OB/FB/FC/DB/UDB structures.

Prevention and Project Hygiene

• Backup cadence: Maintain at least three rolling archive snapshots of the entire project folder, not only .s7p files. Backup tools that exclude hidden/system files will omit the oms\ directory required for cross-reference recovery.
• Antivirus exclusions: Add C:\Program Files\Siemens\Automation\* and the project root to the AV exclusion list. Many AV products quarantine .sec files as "encrypted archive" false positives; verify scan logs if errors recur after a virus-definition push.
• Service Pack currency: SP2 alone is insufficient for projects with more than 100 blocks or with multi-project structures. Apply the highest available hotfix chain (HF7–HF10 depending on release year) to harden the cross-reference subsystem.
• User privilege consistency: Do not switch between administrator and standard-user context when accessing the same project; mixed privilege creates read-only .sec files that the editor cannot update, producing the same diagnostic surface as a missing S7TBROWX.dll.
• Avoid mapping drives: Cross-reference fails silently if the project resides on a UNC path or network-mapped drive lacking write-attribute support. Move the project to local NTFS storage before performing major reorganizations or backups.
• Archive rather than copy: Always exchange a project via File → Archive / Retrieve rather than file-system copy. Archives preserve SZL tables, DB initial values, and reference-data parity; copies routinely lose them, re-introducing the corruption pattern after one round trip.

Migration Considerations: STEP 7 V5.x to TIA Portal

For systems requiring long-term support beyond Windows XP, migration to TIA Portal V17 or later (with the STEP 7 V5.x project migration tool) restores the cross-reference and Go To Location features under the modern Go to → Cross-references and Go to → Usage commands. The migrated project's cross-reference subsystem runs against the TIA Portal XML project database rather than the V5.x .sec/.srs cache, eliminating the entire class of errors documented here. Pre-migration steps:

1. Apply all available hotfixes to the V5.x project.
2. Run a full slow reorganization as in Solution A.
3. Archive the project (File → Archive) rather than copying the folder.
4. Use the TIA Portal migration wizard to import the archive, then verify the cross-reference window in the migrated project as in the Verification section above.

Throughout migration, additional support material and STEP 7 to TIA Portal hand-off guides can be sourced from Siemens Industry Online Support.

Frequently Asked Questions