Resolving TIA Portal HSP Digital Signature Invalid Error

Problem Description

When attempting to install a Hardware Support Package (HSP) in the TIA Portal, the installation aborts with the dialog message:

"The digital signature of the support package HSP <filename> is invalid."

The error is raised by the TIA Portal installer when it cannot validate the cryptographic signature that Siemens attaches to every officially distributed HSP. The HSP never reaches the hardware catalog, leaving the new module types invisible to the device configurator and blocking any subsequent upload or download of projects that reference the missing hardware.

Two field scenarios are commonly reported with this exact wording:

• Scenario A (TIA Portal V11 SP2 Update 3) – an engineer attempts to install the HSP CPU21x V3.0 package to add a S7-1200 CPU 1212C DC/DC/DC (6ES7 212-1AE31-0XB0) firmware V3.0 to the catalog of TIA Portal V11 SP2 Update 3. The installation fails immediately with the signature error.
• Scenario B (TIA Portal V17 SP1) – an engineer installs an ET 200 HSP successfully one day, then attempts to install the HSP for TM Position 2 (6ES7 551-1AB01-0AB0) the next day and the same signature error appears on a project originally saved with plain TIA V17.

In both cases, the HSP download itself is intact and the same package can be installed on a different workstation without any modification. This is a strong indicator that the problem is local to the engineering PC, not to the HSP file.

Affected Products and Versions

Root Cause Analysis

Siemens signs every HSP with a code-signing certificate. The TIA Portal installer verifies the certificate chain against the trusted root certificates stored in the Windows certificate store of the engineering workstation. If the chain cannot be validated, the installer rejects the HSP with the "digital signature is invalid" error.

The three root causes documented by Siemens and reproduced in the field are:

1. PC clock/date tampering or drift. The X.509 certificates that Siemens uses for HSP signing carry a Valid From and Valid To timestamp. If the system date/time of the engineering PC is set incorrectly – either manually set to a date outside the certificate validity window, or drifting due to a failing CMOS battery – the installer will reject the signature even when the file is genuine. This is the most common field cause of intermittent signature errors where the same HSP installs on one PC but not on another.
2. Missing or revoked Siemens root certificate. The Siemens Code Signing Root CA certificate must be present in Trusted Root Certification Authorities > Certificates of the local computer. Anti-virus software, group policy, or an aggressive Windows image can remove or block this certificate, which makes the chain untrusted.
3. Damaged or modified HSP file. The HSP is a signed ZIP-like container. If the download was truncated, copied through a file system that strips extended attributes, or edited in any way (even saving a copy), the signature will no longer match the content hash.

Understanding HSPs and Their Limitations

According to the official Siemens Knowledge Base article 72341852 – Support Packages for the hardware catalog in the TIA Portal (HSP), an HSP is a software package that adds new modules to the hardware catalog of the installed TIA Portal version. HSPs are required whenever you want to configure an S7-1200, S7-1500, ET 200, or SINAMICS module that was released after the original TIA Portal service pack was published.

Two critical limitations must be understood before troubleshooting:

1. HSPs do not enable project upload from a newer CPU. The hardware catalog and the online upload function are decoupled. Installing the HSP for a CPU 1212C V3.0 into TIA V11 SP2 UPD3 makes the device visible in the project tree, but the upload will still fail with "online: unknown CPU type" or a similar error because TIA V11 SP2 UPD3 does not know the V3.0 firmware protocol. To upload a project, you need a TIA Portal version whose original release already supports the firmware of the target CPU.
2. Upload requires the original (or newer) TIA Portal version. This is documented in FAQ 97554052 – Uploading an S7-1200/S7-1500 program. The same rule applies to S7-300/400, ET 200, and SINAMICS targets.

Diagnostic Procedure

Run the following checks in order. Each step isolates a single root cause without requiring an active support ticket.

1. Verify the system date and time. Open Settings > Time & Language > Date & Time on Windows 10/11, or double-click the clock on the taskbar of Windows 7. Confirm that the date, time, and time zone are correct. If automatic time synchronization is enabled, force a resync with w32tm /resync /force from an elevated command prompt. If the system clock has been set forward or backward manually, return it to the correct value and reboot before retrying the HSP install.
2. Check the Siemens root certificate. Open certlm.msc (local machine) or certmgr.msc (current user), navigate to Trusted Root Certification Authorities > Certificates, and look for the Siemens Code Signing Root CA entry. If it is missing, export it from a working workstation (Right-click > All Tasks > Export, format Base-64 encoded X.509 (.CER)) and import it into the affected PC.
3. Re-download the HSP from Siemens. Delete the cached HSP file and re-download it from the Siemens Industry Online Support portal, using the same account that originally downloaded it. Compare the SHA-256 hash with the value displayed on the download page (if provided) to confirm file integrity.
4. Run the installer with elevated rights. Right-click SIAsp > Support Packages in the TIA Portal installation tree, or launch the HSP install from the start menu as Administrator. A denied UAC prompt can produce the same error on locked-down Windows installations.
5. Retry after a reboot. Multiple field reports (including the one in the source thread) confirm that a plain workstation reboot resolves the issue. A locked certificate store, suspended Windows service, or pending Group Policy update is often the trigger, and a reboot releases the lock.

Resolution Steps

Apply the following sequence when the diagnostics above point to a specific cause.

Fix 1 – Restore Correct System Time

1. Open Control Panel > Clock and Region > Date and Time.
2. Click Internet Time > Change Settings and tick Synchronize with an Internet time server.
3. Select time.windows.com (or your corporate NTP source) and click Update now.
4. Confirm the displayed offset is below ±5 seconds. If the CMOS battery is depleted, replace it (CR2032 on most desktop motherboards) before proceeding.
5. Re-launch TIA Portal and install the HSP via Options > Support Packages as documented in the official HSP installation procedure.

Fix 2 – Import the Missing Siemens Root Certificate

1. On a working workstation, open certlm.msc as Administrator.
2. Navigate to Trusted Root Certification Authorities > Certificates.
3. Locate Siemens Code Signing Root CA, right-click and select All Tasks > Export.
4. Choose Base-64 encoded X.509 (.CER) and save the file to a USB stick.
5. On the affected PC, open certlm.msc as Administrator, right-click Trusted Root Certification Authorities > Certificates and choose All Tasks > Import.
6. Follow the wizard, select the .CER file, and place it in the Trusted Root Certification Authorities store.
7. Close TIA Portal completely and retry the HSP install.

Fix 3 – Re-download and Re-install the HSP

1. Browse to the Siemens Industry Online Support portal entry 72341852.
2. Download the exact HSP file again. Do not rename the file; the installer validates the internal manifest path.
3. Verify the file size matches the value on the download page.
4. Install the HSP using the standard menu path: Options > Support Packages, then select Installation of support packages in the dialog.

Fix 4 – Contact Siemens Support

If the three fixes above do not resolve the issue, open a ticket through the official Siemens Industry Online Support request form. Attach:

• A screenshot of the signature error dialog.
• The exact TIA Portal version (e.g., "TIA Portal V17 SP1 Update 2").
• The HSP file name and size.
• The export of the affected certificate chain (right-click the HSP file in Windows Explorer, Properties > Digital Signatures > Details).

Uploading Projects – Version Requirements

The TIA Portal V11 SP2 Update 3 catalog only contains S7-1200 modules with hardware version 2.2 or older. The CPU 1212C DC/DC/DC with order number 6ES7 212-1AE31-0XB0 ships with firmware V3.0, which is post-V2.2 silicon. TIA V11 SP2 UPD3 will never be able to upload the project from this CPU, even after the matching HSP is installed. This is by design, not a bug.

To recover the original project from a CPU 1212C V3.0, the engineering PC must be upgraded to TIA Portal V13 SP1 Update 4 or newer (current recommendation: TIA V17 with the latest available Update). The procedure is described in detail in FAQ 97554052 – Uploading an S7-1200/S7-1500 program.

Troubleshooting Matrix

Verification

After each attempted fix, validate the result with the following checks:

1. Open TIA Portal and navigate to Options > Support Packages. The newly installed HSP must appear in the Installed list with a green check mark.
2. Open the hardware catalog and confirm the new module (e.g., 6ES7 212-1AE31-0XB0 V3.0 or 6ES7 551-1AB01-0AB0) is searchable.
3. Right-click the HSP file in Windows Explorer, choose Properties > Digital Signatures, and confirm that the signature is marked as Valid and that the signer is Siemens AG.
4. Attempt the original upload or download operation. The online dialog should now show the correct CPU type instead of "Unknown device".

If verification still fails, capture the installation log (located under %LOCALAPPDATA%\Siemens\Automation\Logs\ on modern TIA versions) and attach it to the Siemens support ticket. The log file name follows the pattern SupportPackage_<YYYYMMDD>_<HHMMSS>.log.

Best Practices to Avoid Recurrence

• Enable NTP synchronization on every TIA Portal engineering workstation. Group Policy objects should reference the corporate NTP server rather than time.windows.com.
• Do not edit HSP files. The signature covers the file content hash; even a harmless rename inside the ZIP container invalidates the signature.
• Maintain a TIA Portal upgrade roadmap. S7-1200 firmware V4.x and V5.x are only configurable in TIA V15.1 and newer. Plan a step-up to TIA V17 (or the current release) to keep the engineering environment aligned with the plant hardware.
• Image engineering PCs with the Siemens root certificate pre-installed. Capturing the certificate into the master image prevents the symptom on every cloned workstation.
• Document the HSP set installed on every engineering PC. A small change log (date, HSP file, install engineer) makes it easy to correlate a new fault with a Windows update or anti-virus event.