TIA Portal V12: Resolving Grayed-Out Read/Write Access Menu

Problem Overview

In TIA Portal V12 (and adjacent versions V11, V13, V14), engineers working in the LAD/FBD/ST editor of an S7-1200, S7-300, S7-400, or WinCC project occasionally encounter a disabled (grayed-out) command at Go to → Read/Write access. The menu item is visible but cannot be activated, and no tooltip explains why the function is unavailable. This behavior is also observed in TIA Portal V20 when migrating legacy V12 archives or working with TIA Portal Openness scripts that open a project under a read-only security context.

Read/Write access in this context is a project-level security and navigation feature that controls both the ability to modify tags, blocks, and library elements, and the ability to invoke the cross-reference scope commands that depend on a writable project handle. When the entry is grayed out, the integrated engineering environment is signaling that the project was opened in a state that does not permit a write transaction against the project database.

Root Cause Analysis

The Read/Write access command in the Go to menu is part of the navigation logic that interacts with the project handle exposed by the TIA Portal automation framework. The command is bound to a project state flag. When the underlying project is opened in any of the following states, the flag is cleared and the menu item is disabled:

1. Read-only project open — The project is launched from a directory or archive for which the Windows NTFS ACL grants only Read & execute and/or Read permissions to the engineering user. TIA Portal detects the lack of write permission and opens the project in a constrained mode.
2. TIA Portal Openness session — A script compiled against the TIA Portal Openness API opens the project with the DieselProject.OpenReadOnly semantics. Per Siemens documentation, "You can have access to read-only project, but you will not be able to use full set of features that are available to a user with read-write access." This state is sticky for the lifetime of the TIA Portal process.
3. Library opened from a read-only source — Master copies and types in the global library are also governed by the same access flag. If the library archive is on read-only media or in a controlled source-code folder, the per-library Read/Write toggle is grayed out until the library is opened from a writable location.
4. Project under exclusive lock — A second TIA Portal instance holds the project write lock, a multi-user server is the source of truth, or the local *.ap12/*.ap13/*.ap20 archive is flagged with the read-only attribute via Windows Explorer.

Project Access State Matrix

Solution: Restore Write Access to the Project

The primary remediation is to open the TIA Portal project from a location and identity context that allows write operations. The procedure below restores the menu item without reinstalling the engineering software.

Step-by-Step Procedure

1. Close the project in TIA Portal. Do not use Close project in a way that prompts a save — the read-only state will reject the save and leave the project in an indeterminate state.
2. Open Windows Explorer and navigate to the directory that contains the *.ap12, *.ap13, *.ap14, or *.ap20 archive. Right-click the file and select Properties.
3. In the General tab, clear the Read-only attribute checkbox. Click Apply and confirm attribute changes to be applied to all subfolders and files in the project tree.
4. If the project is on a network share, right-click the parent folder, choose Properties → Security → Edit, and verify that the engineering user account has Modify and Write permissions. Domain policy may need to be adjusted through the IT administrator.
5. If the project is under source control (SVN, TFS, Git LFS for TIA add-ons), check out the project files to a writable working copy. Confirm that no .lck or *.lock files remain in the project root.
6. Re-launch TIA Portal V12 (or the active version) and open the project from the Open project dialog. The Go to → Read/Write access command should now be selectable.

Library-Specific Resolution

The same Go to → Read/Write access semantics apply inside the Library Management pane, where the field controls whether the user can edit, add, or overwrite master copies and types in a user library. The default state for a freshly opened library is read-only, because the library is treated as a reference object rather than a working artifact.

Promoting a Library to Read/Write

1. In the project tree, expand Global libraries (or Libraries in V14+).
2. Right-click the library node. Confirm that the path on disk is writable. If the library is stored in %ProgramFiles% or another protected directory, copy it to a user-controlled folder first.
3. Open the library by double-clicking it. The library view loads the master copies and type definitions.
4. Right-click the library root again. The Read/Write access toggle becomes selectable. Choose Read/write access from the context menu.
5. Modify the library as required. The toggle remains in Read/Write for the rest of the session. To persist the choice, save the project (Project → Save or Ctrl+S).

This workflow is the canonical answer to the related support question regarding TIA-13 default system blocks from the system library: the system library is intentionally read-only, and any user library derived from it must be opened in read/write mode before the contents can be edited.

Alternative Navigation Methods

When the Read/Write access command is unavailable but the engineering task only requires navigation rather than modification, TIA Portal V12 and later provide several alternative commands in the Go to submenu and the context menu of the cross-reference editor.

Go To Submenu Alternatives

Cross-Reference Information Workflow

For project-wide visibility into the read and write points of a global address, select the operand in any editor and use one of the following cross-reference entry points. All of these are read-only and remain available even when the Read/Write access command is disabled:

1. Right-click the operand → Cross-reference information (or Cross references in V14+). The cross-reference editor opens in a docked tab.
2. Use the Inspector window: with the operand selected, switch to the Information tab and expand the Cross-reference group.
3. From the menu bar, View → Reference data → Display opens the consolidated reference view for the entire program. The view is read-only and exports to CSV or XML for offline analysis.

TIA Portal Openness API Context

Engineers who automate project creation or migration through the TIA Portal Openness API must explicitly choose between Open and OpenReadOnly on the DieselProject interface. According to the official Siemens TIA Portal Openness documentation, "You can have access to read-only project, but you will not be able to use full set of features that are available to a user with read-write access." The disabled Go to → Read/Write access command is one observable consequence of this design.

The read-only restriction in an Openness session applies to:

• Modifying tags, blocks, watch tables, and force tables
• Adding, deleting, or renaming devices in the device configuration
• Updating cross-reference data (the cross-reference editor opens in snapshot mode)
• Saving the project back to its source archive

To regain full access from a scripted workflow, close the read-only DieselProject handle and re-open the project with a write-enabled Openness session. The relevant entry point is documented at Accessing read-only TIA Portal project.

Openness API — C# Example

using Siemens.Engineering;
using Siemens.Engineering.Project;

public static class ProjectAccess
{
    public static Project OpenForWrite(TiaPortal tia, FileInfo archive)
    {
        // OpenWithUpgrade prompts for version migration; returns writable Project
        return tia.Projects.Open(archive);
    }

    public static Project OpenReadOnlySafe(TiaPortal tia, FileInfo archive)
    {
        // Read-only handle; Go To → Read/Write access will be disabled
        return tia.Projects.OpenReadOnly(archive);
    }
}

Version-Specific Behavior

Field reports from V11 SP2 through V20 indicate that the disabled Read/Write access item is present in the Go to submenu in every version, but the underlying read-only detection logic has been tightened over time.

Verification Procedure

1. Open the project in TIA Portal with administrative or engineering credentials that include NTFS Modify permission on the project directory.
2. In an SCL or LAD/FBD block, place the cursor on a tag such as "Motor_On" (Boolean tag in a default tag table).
3. Right-click and select Go to → Read/Write access. The command should now be active.
4. Confirm that the cross-reference editor opens and lists the operand with separate R (read), W (write), and RW columns.
5. Repeat the test on a library master copy to verify the library toggle is available in the context menu.

Troubleshooting Matrix

Best Practices

• Store TIA Portal projects on a network share with explicit Modify ACLs for engineering users. Avoid placing projects in %ProgramFiles%, C:\Users\Public, or other directories subject to UAC virtualization.
• When using TIA Portal Openness for batch migration, always close the read-only handle after read-only operations and re-open with a write handle before applying changes.
• Use View → Reference data → Display for read-only inspection; reserve Go to → Read/Write access for the navigate-and-edit workflow.
• Periodically audit the project directory for stray .lck files that can simulate a lock state and disable write operations.
• Document library read-only state in team procedures. A library that is silently read-only is a common source of confusion when type modifications appear to be discarded.