Fixing TIA Portal V17 WinCC Project Opening Error Path and Rights

Problem Overview

Siemens TIA Portal V17 (and matching WinCC V17) projects occasionally fail to open with the dialog:

"An error occurred while opening. Please check the network connection, access rights, length of used paths, and/or read only state of the project files and folders."

The message is generated by the TIA Portal project manager (TiaPortal.exe) when the Siemens.Automation.Portal.ProjectManagement component cannot bind a session to the underlying .ap17 / .tia17 archive. In some fault paths the dialog appears immediately on the Open Project view before any file is selected; in others it surfaces after the user clicks a project shortcut on a corporate share.

This fault class is distinct from a WinCC runtime startup error or a TIA Portal installer error. The project archive is intact on disk; the failure is in the project manager's ability to read, write, or lock the working copy.

Error Message Anatomy

Each clause in the dialog corresponds to a discrete validation that the portal performs against the candidate project folder. Mapping the wording to the actual check is the fastest path to root cause:

Always treat the message as a four-part checklist, not a single root-cause indicator. Fix all four before re-opening.

Affected Versions and Update Levels

The fault has been observed across the following TIA Portal V17 builds:

• TIA Portal V17 (Entry ID 109769772) – initial release
• TIA Portal V17 Update 1 through Update 5 (Entry ID 109784440)
• WinCC V17 RT/RC (Entry ID 109748955)

Root Cause Matrix

Diagnostic Procedure

1. Open Event Viewer → Windows Logs → Application and filter for source Siemens TIA Portal. Note the most recent .NET Runtime or HRESULT exception.
2. Open the project folder and inspect the latest PortalEventLog.xml. This is regenerated every session and lives under %LOCALAPPDATA%\Siemens\Automation\Log\.
3. Run fsutil 8dot3name query C: to verify short-name generation. TIA Portal V17 occasionally fails to bind System\*.sys files when 8.3 names are stripped on the volume.
4. Capture a Process Monitor trace filtered for TiaPortal.exe and look for RESULT = ACCESS DENIED or RESULT = PATH NOT FOUND against *.ap17, *.tia17, or *.lock.
5. Verify the project archive's MD5/SHA-1 against the last-known-good backup. A corrupted archive displays the same dialog but requires project recovery, not path/rights repair.

Path Length and Character Set Constraints

TIA Portal V17 still uses Win32 file APIs internally and inherits the legacy MAX_PATH = 260 cap on most dialogs, even when the application manifest has longPathAware enabled. Practical rules:

• Keep the absolute path under 200 characters from drive root to .ap17 file. This provides headroom for the auto-generated \System\<GUID>\ subfolders that TIA creates on first open.
• Use ASCII only. The following characters are guaranteed safe: A–Z a–z 0–9 _ -. Avoid spaces, although they are technically tolerated when the path is quoted.
• Never place the project under Desktop, Documents, or OneDrive\Documents – these default folders already consume 30+ characters and frequently contain the user profile SID.
• Recommended canonical location: C:\Automation\<ProjectName>\<ProjectName>.ap17. If the project is WinCC Comfort/Advanced, also accept C:\Automation\<ProjectName>\<ProjectName>.tia17 for HMI-only archives.

Reference: Microsoft Maximum Path Length Limitation (Win32 documentation) confirms the 260-character limit when long-path-aware opt-in is not honored by every internal API call.

File-System Permissions and Read-Only Attributes

Even when the path is short and local, two permission failures dominate:

2.1 NTFS Effective Permissions

Open secpol.msc or run icacls "C:\<project>" and confirm the following ACE on every file:

BUILTIN\Administrators:(OI)(CI)(F)
NT AUTHORITY\SYSTEM:(OI)(CI)(F)
<DOMAIN>\<USER>:(OI)(CI)(M)

The (M) modify ACE is required because TIA Portal rewrites the .ap17 archive when saving. A user with (R) read-only ACE will trigger the dialog even though the project appears to open.

2.2 Read-Only Attribute

attrib -R "C:\Automation\<ProjectName>\*.ap17"
attrib -R "C:\Automation\<ProjectName>\*.tia17"
attrib -R /S /D "C:\Automation\<ProjectName>\"

Network Drive vs Local Storage

Siemens explicitly states in the TIA Portal help that projects should be opened from a local NTFS volume. The recommendation is repeated in the portal online help under Working with projects → Storage locations and referenced in Entry ID 109769772.

Reasons for the restriction:

• The portal opens the .ap17 archive in FILE_SHARE_NONE mode for the duration of the editing session. SMB1/SMB2 share-mode semantics differ slightly from NTFS and can return spurious ERROR_SHARING_VIOLATION.
• Working-copy lock files under \<project>\System\*.lock use rename-as-lock semantics, which are unreliable across \server\share\DFS\dfsroot\... referrals.
• DFS-R and FRS-replicated shares rewrite file timestamps mid-session, invalidating the portal's XmlDocument cache.

If corporate policy mandates network storage, work around the limitation by:

1. Opening the project locally.
2. Archiving to network share with Project → Archive → To file system on a controlled schedule.
3. Re-opening from the local copy the next session.

Corporate Settings and Registry Constraints

The TIA Portal supports centralized configuration through TIA Portal Administrator (Entry ID 109740887). When a GPO pushes global settings, the local registry hive is overwritten at every launch:

HKLM\SOFTWARE\Siemens\Automation\Portal\V17\Settings
    UseGlobalSettings = 1
    GlobalSettingsPath = \\\corp.local\TIA\Settings.tps
    DisableLocalUserFolders = 1

When UseGlobalSettings = 1, the local user profile under %LOCALAPPDATA%\Siemens\Automation is ignored. If the share hosting Settings.tps is unreachable, the portal may still launch but fails to bind the project management component, surfacing as the "error while opening" dialog.

Repair the TIA Portal install from Control Panel → Programs → Siemens TIA Portal V17 → Repair. The repair operation rebuilds the default registry hive without touching user projects. Allow 10–20 minutes for completion.

Hardware / Motherboard Swap Implications

When the boot drive is migrated from one PC to another (typical after a motherboard failure), Windows retains the original driver signature database but loses hardware binding for the new chipset. Three classes of failure follow:

1. Storage controller driver mismatch. The drive is now attached via a different SATA / NVMe controller. StorAHCI.sys or StorNVMe.sys timing differences cause partial-sector read failures. TIA Portal reports them as IOException and shows the open-project dialog.
2. Volume Shadow Copy (VSS) writers absent. Windows Search indexer and VSS rely on the original chipset driver set. After a swap, run vssadmin list writers and re-register any failed writer with cd /d C:\Windows\System32 & regsvr32 /i ole32.dll.
3. Trusted Platform Module (TPM) state mismatch. BitLocker may mount the volume read-only until recovery key is supplied, again producing the read-only clause in the error dialog.

After verifying data integrity with chkdsk C: /scan, install the new motherboard's chipset, Intel Management Engine (ME) or AMD Platform Security Processor (PSP), and storage controller drivers from the OEM's support site before re-launching TIA Portal.

Step-by-Step Recovery Procedure

1. Update TIA Portal. Apply the latest V17 HSP via Siemens Automation License Manager → TIA Portal → Check for updates. Reference Entry ID 109740887.
2. Verify project integrity. Right-click <project>.ap17 → Properties → Previous Versions tab. If shadow copies exist, restore to a working timestamp.
3. Copy to a clean local path.

   mkdir C:\Automation
   xcopy /E /H /K \\\server\share\<project> C:\Automation\Test\
   cd C:\Automation\Test
   ren <project>.ap17 Test.ap17

4. Strip read-only attributes.

   attrib -R /S /D "C:\Automation\Test\"

5. Reset NTFS ownership.

   takeown /F "C:\Automation\Test" /R /D Y
   icacls "C:\Automation\Test" /grant %USERNAME%:F /T

6. Remove stale locks.

   del /S /Q "C:\Automation\Test\System\*.lock"

7. Open directly from explorer. Double-click Test.ap17. Do not start TIA Portal first and then browse for the project; this forces a clean project-binding path.
8. Capture the resulting log. On first successful open, TIA Portal writes a baseline PortalEventLog.xml. Archive this alongside the project for future diagnostics.

Verification Checklist

Preventive Configuration

Apply these settings once per engineering workstation to avoid recurrence:

• Configure Windows to disable Auto-Trigger of OneDrive Files-On-Demand for any folder containing TIA projects (OneDrive → Settings → Sync and back up → Files On-Demand → uncheck "Save space and download files as you use them").
• Add the project root and %ProgramFiles%\Siemens\Automation to the antivirus exclusion list. Coordinate with the EDR administrator; documented exclusions are mandatory for industrial control software per IEC 62443.
• Disable 8.3 name generation on the project volume: fsutil 8dot3name set C: 1. This prevents TIA Portal from binding to the short SYSTEM~1 alias that disappears after a project migration.
• Enable Long Path support via Group Policy: Computer Configuration → Administrative Templates → System → Filesystem → Enable Win32 long paths. Although TIA Portal V17 does not fully utilize long paths, enabling the policy removes the most common path-length dialog source.
• Schedule nightly project archive using TIA Portal Openness API or the S7-PCT scripting interface to a dedicated, NTFS-formatted local volume.

Frequently Asked Questions