Resolving Siemens STEP 7 V5.5 SP4 Error 13:5581 During HW Catalog Update

Error 13:5581 in SIMATIC STEP 7 V5.5 SP4 (and earlier V5.x service packs) is a failure code returned by the Hardware Configuration (HW Config) "Update Catalog from Internet" function. The dialog opens, attempts to contact the Siemens Industry Online Support (SIOS) server, and aborts with the popup bearing the message text "Error 13:5581" before any Hardware Support Package (HSP) is downloaded. This article documents the meaning of the error, the conditions that produce it, the ordered recovery steps, and the verification checks an engineer should run before the system is considered healthy.

1. Problem Description

The standard symptom chain, reported in the field, looks like the following:

1. The engineer opens SIMATIC Manager > HW Config.
2. The menu path Options > Update Catalog is selected (or the user clicks the "Install HW Updates ..." button on the toolbar).
3. The "Find and Install Hardware Updates" wizard appears with the options Update from Internet and Update from local file system / CD / DVD.
4. Selecting Update from Internet produces the popup "Error 13:5581" (sometimes displayed as a numeric code 13:5581 with an OK button and a Siemens red stop icon).
5. Reinstalling STEP 7 V5.5 SP4 over the existing installation does not change the behavior.
6. Manual HSP import from a local directory is reported as "procedure does not complete."

Affected versions confirmed by field reports include STEP 7 V5.5 SP1, SP2, SP3, and SP4. The condition is platform independent (Windows XP SP3, Windows 7 32/64-bit, Windows Server 2003/2008 R2 have all been reported in support tickets).

2. Error 13:5581 - Technical Meaning

Within the STEP 7 V5.x framework, the high-byte of the colon-separated error code identifies the component that raised the failure, and the low-byte identifies the specific cause. For 13:5581:

The low-word 5581 historically maps to a generic transport failure inside the S7Webupd / Step7 Web Update ActiveX bridge, which in STEP 7 V5.5 SP4 is built on the Microsoft WinHTTP stack. When the bridge cannot complete a TLS handshake, cannot resolve the DNS entry, or cannot traverse a corporate proxy, the wizard substitutes the friendly code 13:5581 instead of surfacing the raw WinHTTP error (for example, ERROR_WINHTTP_CANNOT_CONNECT 12029, ERROR_WINHTTP_TIMEOUT 12002, or HTTP 407 Proxy Authentication Required).

3. Root Cause Analysis

Five root causes are observed in order of frequency in the field:

1. No outbound HTTP/HTTPS from the engineering station. The S7Webupd service attempts a direct connection on TCP 443 to support.industry.siemens.com. If the workstation is on a closed industrial network, on a VPN without split tunneling, or behind a stateful firewall that blocks the Java/ActiveX control the wizard embeds, the connection is refused before the TLS handshake completes.
2. Corporate proxy not configured in Windows Internet Options. STEP 7 V5.5 does not read its own proxy setting; it uses the system-wide WinHTTP default proxy, which is populated from Internet Explorer > Internet Options > Connections > LAN Settings. If the proxy is set in the browser but "Bypass proxy server for local addresses" excludes the Siemens host, the update fails.
3. TLS / cipher mismatch. Windows XP SP3 and early Windows 7 builds ship with TLS 1.0 only. Siemens discontinued TLS 1.0 on the support portal in stages starting in 2017; if the engineering station cannot negotiate TLS 1.2 (or has an outdated root CA store), the handshake fails and the wizard reports 13:5581.
4. Corrupted local HSP cache. The local cache lives in C:\Program Files\Siemens\Automation\S7BIN\s7hspcache (or ...\S7WBIN for some installs) and in the registry key HKLM\SOFTWARE\Siemens\Automation\STEP7\HSP. A partially written or truncated cache will cause the wizard to abort with 13:5581 even when network connectivity is fine.
5. Local HSP import also fails ("procedure does not complete"). This is the strongest indicator that the cause is not network-related at all. It points to a corrupted STEP 7 installation, missing or mismatched Windows redistributables, or a damaged registry hive, and is the case the original poster ultimately described.

4. Prerequisites for Recovery

Before starting the corrective action, capture the following so the fix can be rolled back if needed:

• A full STEP 7 V5.5 SP4 installation DVD or ISO (must be the exact service pack; SP4 cannot be applied on top of SP1 without the intermediate SP2/SP3).
• Administrative rights on the engineering station.
• All HSP files you expect to deploy, downloaded once from a known-good machine to a USB drive or network share. Current HSP collections are published by Siemens under entry ID 23183356 - STEP 7 V5.x Hardware Support Packages (HSPs).
• A backup of the S7 project archives that exist on the workstation.
• License keys (Step7 Professional, optional S7-PLCSIM, S7-Technology, S7-SCL, S7-GRAPH) exported via the Automation License Manager.

5. Solution Path A - Configure the Network Channel

Use this path first when only the Internet update fails and the manual HSP import works.

5.1 Configure the WinHTTP proxy

1. Open Internet Explorer > Internet Options > Connections tab > LAN Settings.
2. If the network uses a forward proxy, tick Use automatic configuration script or Use a proxy server for your LAN and enter the FQDN and port (typically 8080 or 3128).
3. Click Advanced and add support.industry.siemens.com, *.industry.siemens.com, and *.automation.siemens.com to the exception list only if traffic to those hosts should bypass the proxy.
4. Click OK twice and close IE.
5. Open an elevated command prompt and run:
   netsh winhttp import proxy source=ie
   This copies the IE proxy into the WinHTTP store that STEP 7 reads.
6. Verify with:
   netsh winhttp show proxy
7. Test reachability with:
   certutil -urlcache -split -f https://support.industry.siemens.com/cs/document/23183356 test.s7hsp

5.2 Enable TLS 1.2 on legacy operating systems

For Windows 7 SP1 without KB3140245, TLS 1.2 client support must be enabled by registry. The relevant keys live in HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client and must contain Enabled=1 and DisabledByDefault=0. For Windows Server 2008 R2 the same update is delivered as KB3140245. After applying the update, reboot before retrying the catalog update.

5.3 Clear the local HSP cache

1. Close SIMATIC Manager.
2. Stop the service S7WNFSERV (NetPro synchronization) if it is running.
3. Rename the directory %ProgramFiles%\Siemens\Automation\S7BIN\s7hspcache to s7hspcache_old.
4. Open regedit and export HKLM\SOFTWARE\Siemens\Automation\STEP7\HSP for backup, then delete the subtree.
5. Restart the PC, open HW Config, retry the update.

6. Solution Path B - Install HSPs from a Local Source

If the Internet channel is unavailable but the installation media is intact, this path avoids the Web update entirely.

1. On a machine with Internet access, navigate to the Siemens support portal and download the current HSP collection for STEP 7 V5.5 (entry 23183356). The bundle typically ships as S7HSP5x_*.exe self-extractors.
2. Copy the extracted .hsp and .xml files to a USB drive or a shared network directory, for example D:\Siemens_HSP\.
3. On the engineering station, open SIMATIC Manager > HW Config.
4. Select Options > Install HW Updates.
5. In the dialog, choose Update from local file system / CD / DVD and browse to the directory created in step 2.
6. Select the HSPs that match the hardware you are commissioning. The dialog shows the version of the catalog already installed; only install a higher version.
7. Click Install. A progress bar shows the HSP being merged into the master catalog STEP7_V55.HSP in the S7BIN directory.
8. When the dialog returns to idle, close HW Config and re-open it to confirm the new catalog entries appear under the corresponding catalog drawers (e.g. SIMATIC 300 > CPU-300, SIMATIC 400 > CPU-400H).

7. Solution Path C - Repair or Reinstall STEP 7

Use this path when both the Internet update and the local HSP import fail, which is the precise symptom set reported in the source case. The order is: STEP 7 repair, then full STEP 7 reinstall, then OS reinstall as the last resort.

7.1 STEP 7 repair in place

1. Insert the STEP 7 V5.5 SP4 installation DVD (or mount the ISO).
2. Run Setup.exe from the root of the media.
3. Choose Repair Installation when prompted.
4. Accept the default component selection and complete the wizard.
5. Reboot and retry the HSP import.

7.2 Full STEP 7 reinstall

1. Open Control Panel > Programs and Features and uninstall all STEP 7 components (STEP 7 V5.5, S7-PLCSIM, S7-SCL, S7-GRAPH, S7-Technology, Automation License Manager, S7-PCT, S7-Distributed Safety) in the reverse order they were installed.
2. Reinstall from the media in the recommended order: Automation License Manager > STEP 7 V5.5 > SP4 > optional packages.
3. Import the exported license keys back via the Automation License Manager.
4. Reinstall the current HSP collection from the local source as described in Section 6.

7.3 Operating system reinstall

If the full STEP 7 reinstall does not resolve the 13:5581 / "procedure does not complete" combination, the fault is in the Windows installation (corrupted Winsock catalog, mismatched runtime libraries, root certificate store issues, or a domain policy that is blocking the S7 Web Update service). Re-image the workstation from a known-good Windows 7 64-bit or Windows 10 (with STEP 7 V5.6) image, apply the latest Windows updates, and reinstall STEP 7 from clean media. This is the only reliable remediation when the OS itself is suspect.

8. Verification

After applying any of the recovery paths, run the following checks before signing the workstation back into production:

1. Catalog update completes without error. In HW Config, Options > Update Catalog > Update from Internet returns a list of available HSPs and downloads at least one without raising 13:5581.
2. HSP appears in the catalog. Open HW Config and confirm a previously missing module (e.g. a CPU 1515-2 PN added through HSP for early STEP 7 V5.5) now appears in the catalog drawer.
3. S7 web service is reachable. From the engineering station, browse to https://support.industry.siemens.com in Internet Explorer and confirm the page loads without certificate warnings.
4. WinHTTP proxy is correct. netsh winhttp show proxy returns the expected proxy FQDN or "Direct access (no proxy server)".
5. License keys are valid. Automation License Manager shows the Step7 Professional license and any optional package licenses as green.
6. Project round-trip. Open an existing STEP 7 project, perform a download to a test PLC (or S7-PLCSIM instance) and verify that the hardware configuration compiles and downloads without errors.

9. Related Diagnostics Matrix

10. Field-Proven Caveats

• STEP 7 V5.5 cannot consume HSPs intended for STEP 7 V5.6 or for the TIA Portal (HSP files starting with S7HSP6x_ or HSP_TIA). The wizard silently aborts with 13:5581 when an incompatible bundle is selected.
• The "Update from Internet" function relies on the embedded Java runtime in STEP 7 V5.5 (JRE 1.4 era). If the JRE has been disabled by an IT hardening policy, the wizard cannot complete even if network access is fine.
• On Windows 10 1809 and newer, STEP 7 V5.5 SP4 requires the SIMATIC compatibility mode patches. Without them, the S7 Web Update service fails to start and 13:5581 is the visible result.
• Do not run the update wizard while the SIMATIC Logon / Central User Management service is being reconfigured; the dialog shares a registry mutex with that service and can deadlock.
• Always verify the HSP digital signature. Siemens HSPs are signed by "Siemens AG, Industrial Security". Unsigned files are a strong indicator of corruption or tampering and should be deleted.