PySide6 6.11.1: qtquickshapesdesignhelpersplugin.dll not found

[fafafa]

Hello, I'm having an issue using QtQuick.Shapes.DesignHelpers.
Every other module works fine but when I import this one I get an error telling the specified module is not found (see below), even though the dll actually exists.

Here is a minimal version to reproduce the problem:

# main.py
import sys

from PySide6.QtGui import QGuiApplication
from PySide6.QtQml import QQmlApplicationEngine

app = QGuiApplication(sys.argv)
engine = QQmlApplicationEngine()
engine.load("Main.qml")

if not engine.rootObjects():
    sys.exit(-1)
sys.exit(app.exec())

// Main.qml
import QtQuick
import QtQuick.Shapes.DesignHelpers

Window {
    visible: true
}

Environment:

• Windows 11 25H2
• Python 3.11.4 (but i replicated the problem on another computer using Python 3.14.6)
• PySide 6.11.1 (but i replicated the problem with older versions)
• uv package manager and its .venv (but i replicated the problem with pip)

Here is the full console:

PS C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers> ls


    Répertoire : C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
d-----        04/08/2026     19:27                .venv
-a----        04/08/2026     19:27              5 .python-version
-a----        05/08/2026     11:20            260 main.py
-a----        05/08/2026     11:59             87 Main.qml
-a----        05/08/2026     11:54            220 pyproject.toml
-a----        05/08/2026     11:54           3775 uv.lock


PS C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers> uv tree
Resolved 3 packages in 5ms
temp-test-qtquick-shapes-design-helpers v0.1.0
└── pyside6-essentials v6.11.1
    └── shiboken6 v6.11.1
PS C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers> python --version
Python 3.11.4
PS C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers> ls C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers\.venv\Lib\site-packages\PySide6\qml\QtQuick\Shapes\DesignHelpers


    Répertoire: C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers\.venv\Lib\site-packages\PySide6\qml\QtQu
    ick\Shapes\DesignHelpers


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a----        04/08/2026     19:30          24157 plugins.qmltypes
-a----        04/08/2026     19:30            295 qmldir
-a----        04/08/2026     19:30          30520 qtquickshapesdesignhelpersplugin.dll


PS C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers> uv run .\main.py
QQmlApplicationEngine failed to load component
file:///C:/Users/favierl/Documents/temp_test_qtquick_shapes_design_helpers/Main.qml:2:1: Cannot load library C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers\.venv\Lib\site-packages\PySide6\qml\QtQuick\Shapes\DesignHelpers\qtquickshapesdesignhelpersplugin.dll: Le module spÚcifiÚ est introuvable.

[fafafa]

Solved in PySide 6.11.2

[Nils Sjoberg]

Add the following code into your main.py file immediately after creating the engine:

import os
from pathlib import Path
from PySide6.QtCore import QCoreApplication


app = QGuiApplication(sys.argv)
engine = QQmlApplicationEngine()

pyside_qml_path = Path(sys.site_packages) if 'site_packages' in globals() else Path(sys.executable).parent / "Lib" / "site-packages" / "PySide6" / "qml"

qml_import_path = Path(__file__).parent / ".venv" / "Lib" / "site-packages" / "PySide6" / "qml"
if qml_import_path.exists():
    engine.addImportPath(str(qml_import_path))

engine.load("Main.qml")
if not engine.rootObjects():
    sys.exit(-1)
sys.exit(app.exec())

[fafafa]

@Nils-Sjoberg I get the same error as before.

Other modules such as QtQuick, QtQuick.Layouts, QtQuick.Controls and even QtQuick.Shapes are imported without errors.

[Nils Sjoberg]

Try installing the full PySide6 package instead of the essentials:

[fafafa]

@Nils-Sjoberg Same error as before.

PS C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers> uv tree
Resolved 5 packages in 2ms
temp-test-qtquick-shapes-design-helpers v0.1.0
└── pyside6 v6.11.1
    ├── pyside6-addons v6.11.1
    │   ├── pyside6-essentials v6.11.1
    │   │   └── shiboken6 v6.11.1
    │   └── shiboken6 v6.11.1
    ├── pyside6-essentials v6.11.1 (*)
    └── shiboken6 v6.11.1
(*) Package tree already displayed
PS C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers> uv run .\main.py
QQmlApplicationEngine failed to load component
file:///C:/Users/favierl/Documents/temp_test_qtquick_shapes_design_helpers/Main.qml:5:1: Impossible de charger la bibliothÞque C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers\.venv\Lib\site-packages\PySide6\qml\QtQuick\Shapes\DesignHelpers\qtquickshapesdesignhelpersplugin.dllá: Le module spÚcifiÚ est introuvable.

[SGaist]

Hi and welcome to devnet,

Some maybe silly questions:

• The error states that the dll is missing, but you say it's there. Is it located where the message states it is missing ?
• Can you check whether all the dependencies of this dll are findable ?

[fafafa]

Hello @SGaist,

The error states that the dll is missing, but you say it's there. Is it located where the message states it is missing ?

From my first message, the dll is located at:

C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers\.venv\Lib\site-packages\PySide6\qml\QtQuick\Shapes\DesignHelpers\qtquickshapesdesignhelpersplugin.dll

While the message states that it is missing at:

C:\Users\favierl\Documents\temp_test_qtquick_shapes_design_helpers\.venv\Lib\site-packages\PySide6\qml\QtQuick\Shapes\DesignHelpers\qtquickshapesdesignhelpersplugin.dll

So this is the same path.

Can you check whether all the dependencies of this dll are findable ?

I don't know how to do that. However I checked if I could use the QtQuick.Shapes.DesignHelpers via a C++ application, not PySide6, and i can!
Interestingly, replacing the DesignHelpers folder from the .venv with the one used when compiling C++ has no effect.

Does this module work on your machines with PySide6?
I even tried on a Linux computer and I still get the same error. I hope I'm doing something wrong.

[Nils Sjoberg]

When PySide6 loads a QML plugin, the plugin DLL attempts to load additional Qt DLLs located in the main PySide6 directory (or PySide6/Qt/bin). If these paths are not registered in Python's DLL loading mechanism, the tractor will fail to load.

[SGaist]

@fafafa You can use a tool such as Dependencies to check what your executable/dll needs.

It also fails on macOS because of a missing framework so I am thinking that this is a packaging issue.

You can also start you script using QT_DEBUG_PLUGINS=1 python main.py to have more information about what is happening.

[fafafa]

@SGaist Using Dependencies, we see that qtquickshapesdesignhelpersplugin.dll depends on:

• Qt6Qml.dll
• Qt6Core.dll
• Qt6QuickShapesDesignHelpers.dll

But Qt6QuickShapesDesignHelpers.dll doesn't exist in the PySide6 package.
However it does exist in the C++ version which is why it was working in that case.

I reported the bug at https://qt-project.atlassian.net/browse/PYSIDE-3417
Thank you for your help.

[SGaist]

Thanks !

Can you also update your two example files over there ? This will allow to more quickly set things up to test for the person taking the ticket on.

[fafafa]

Solved in PySide 6.11.2