QML runtime error: module "Qt5Compat.QtGraphicalEffects" is not installed

[Aleksey_K]

Conversation with ChatGPT

Had above runtime error today, and since I have not found useful tips to solve here or on Stackoverflow, so I've asked ChatGPT for the help. Live the result here in case somebody needs it in furure.

User:

In my QML file I have following lines:

import QtQuick.Controls.Styles
import Qt5Compat.QtGraphicalEffects

and on running my app I get QML errors:

• module "QtQuick.Controls.Styles" is not installed
• module "Qt5Compat.QtGraphicalEffects" is not installed

while I have added Core5Compat and QuickControls2 components to my CMakeLists.txt:

find_package(
    Qt6 6.8.2
    COMPONENTS Core Quick Gui Qml Core5Compat QuickControls2
    REQUIRED)

target_link_libraries(
    Qt6::Core
    Qt6::Gui
    Qt6::Qml
    Qt6::QuickControls2
    Qt6::Core5Compat)

So why this errors occurred? How to fix them?

ChatGPT:

Thank you for clarifying that you are using Qt 6.8.2 on Ubuntu 22.04 and the installation is correctly set up. Given that you've already verified your Qt installation and all other Qt components are working, the issue likely lies with the QML module dependencies you're trying to use.

Key Points to Address

1. QtQuick.Controls.Styles in Qt 6:

   • The module QtQuick.Controls.Styles was deprecated and removed in Qt 6. Instead, QtQuick.Controls in Qt6 includes style-related functionality directly.
   • If you're using Qt 6, QtQuick.Controls.Styles is no longer available. You should remove or replace its usage with style-related properties within QtQuick.Controls.

2. Qt5Compat.QtGraphicalEffects in Qt 6:

   • The Qt5Compat module is specifically for ensuring compatibility between Qt5 and Qt6. If you're using Qt6, it's important to understand that Qt6 no longer includes the Qt5-compatible graphical effects, so Qt5Compat.QtGraphicalEffects may not work as you expect.
   • If you need graphical effects (such as Blur, DropShadow, etc.) in Qt6, you should use the equivalent modules in Qt6, such as QtGraphicalEffects (introduced in Qt6).

What You Can Do

1. Remove or Replace QtQuick.Controls.Styles:

   • For QtQuick.Controls style handling in Qt6, you no longer need a separate Styles import. Simply use QtQuick.Controls to style your controls. For example, themes or custom styles should be configured directly within QtQuick.Controls.

   Example:

   import QtQuick.Controls 2.15 // For Qt 6, use version 2.15 or your installed version
   

   You can use the ApplicationWindow or Button styles directly with QtQuick.Controls:

   import QtQuick.Controls 2.15
   
   ApplicationWindow {
       visible: true
       width: 640
       height: 480
       title: qsTr("Hello World")
   
       Button {
           text: "Click Me"
           onClicked: {
               console.log("Button clicked")
           }
       }
   }
   

2. Replace Qt5Compat.QtGraphicalEffects:

   • If you want to use graphical effects in Qt6, use Qt6::Qml::GraphicalEffects instead of Qt5Compat.QtGraphicalEffects.

   Example:

   import QtQuick 2.15
   import QtQuick.Controls 2.15
   import QtGraphicalEffects 1.15 // Available in Qt 6
   
   Rectangle {
       width: 200
       height: 200
       color: "red"
       DropShadow {
           anchors.fill: parent
           horizontalOffset: 4
           verticalOffset: 4
           color: "black"
           radius: 10
       }
   }
   

3. Ensure You’re Using the Correct Import for Qt6 Graphical Effects:

   • For Qt6, QtGraphicalEffects is part of the QtQuick module, but you need to explicitly import it.

   Example:

   import QtQuick 2.15
   import QtGraphicalEffects 1.0 // This is for graphical effects in Qt6
   

4. Update Your CMakeLists.txt (Optional):

   • If you haven't done so already, ensure that Qt6::Core and Qt6::Quick are linked properly, as well as the graphical effects component in the case of Qt6.

   target_link_libraries(
       your_target
       Qt6::Core
       Qt6::Gui
       Qt6::Qml
       Qt6::Quick
       Qt6::QuickControls2
       Qt6::GraphicalEffects   # If you're using Qt6 graphical effects
   )
   

Final Notes:

• For Qt6, avoid using Qt5Compat unless absolutely necessary. Instead, use the updated Qt6 alternatives.
• Graphical Effects: Since Qt5Compat.QtGraphicalEffects is not available in Qt6, you’ll need to adjust your QML code to use Qt6's native graphical effects or find alternative solutions depending on your project requirements.
• Styles: Qt6 doesn't separate QtQuick.Controls.Styles, so you’ll handle styling directly within QtQuick.Controls.

This should resolve the errors you're encountering. Let me know if you need further assistance!

---

User:

I use Qt 6.8.2 and it is installed in my Ubuntu 22.04 via Qt Maintenance and all other Qt components installed and work fine, so it is not QT installation or path issue.

ChatGPT:

Thank you for clarifying that you are using Qt 6.8.2 on Ubuntu 22.04 and the installation is correctly set up. Given that you've already verified your Qt installation and all other Qt components are working, the issue likely lies with the QML module dependencies you're trying to use.

1. Verify Qt Installation for QtGraphicalEffects

First, ensure that QtGraphicalEffects is installed as part of your Qt6 installation.

In your Qt installation directory, look under the qml folder to see if QtGraphicalEffects is present. Typically, the path would look like:

/path/to/Qt6/qml/QtGraphicalEffects/

If this module is not present, you may need to explicitly install it. If you're using Qt Maintenance Tool, check if there are any additional components related to graphical effects that you may need to install.

On Ubuntu, you may also need to install qt6-graphicaleffects if it’s available through your package manager:

sudo apt-get install qt6-graphicaleffects

2. Check CMake Configuration for Qt6

The error Failed to find required Qt component "GraphicalEffects" typically occurs when CMake cannot find the module in the expected Qt6 directories. There may be a mismatch in the way you're invoking find_package(Qt6) or missing Qt6 configuration files.

Ensure you're using the correct path to the Qt6 configuration files in CMakeLists.txt. If QtGraphicalEffects is part of your Qt installation, but CMake can't find it, you may need to explicitly set the CMAKE_PREFIX_PATH or Qt6_DIR in your CMake configuration.

For example, make sure the CMAKE_PREFIX_PATH is set to the correct Qt installation directory:

set(CMAKE_PREFIX_PATH "/path/to/Qt6/lib/cmake/Qt6")

3. Check if GraphicalEffects is Available in Qt6

As of Qt 6, graphical effects should be part of the QtQuick module and QtGraphicalEffects should not need to be a separate module. If QtGraphicalEffects isn't found as a separate module, you may need to adjust your usage.

Note: In Qt6, QtQuick itself may provide graphical effects like DropShadow and Blur, and QtGraphicalEffects may not exist as a separate module. For Qt6, you may not need to link against a GraphicalEffects component at all.

4. Update the CMake Configuration (Without GraphicalEffects)

Since QtGraphicalEffects is not always explicitly listed as a separate module in Qt6, we might be able to work around this by relying on QtQuick's built-in effects, as Qt6 has integrated graphical effects into QtQuick rather than separating them into a different module.

You could try removing the dependency for QtGraphicalEffects entirely from your CMake configuration and see if the graphical effects (like DropShadow) work through the QtQuick module.

Here’s an updated CMake configuration without the explicit GraphicalEffects module:

find_package(Qt6 6.8.2 REQUIRED COMPONENTS Core Gui Qml Quick QuickControls2)

target_link_libraries(your_target
    Qt6::Core
    Qt6::Gui
    Qt6::Qml
    Qt6::Quick
    Qt6::QuickControls2
)

5. Testing Graphical Effects in QML

Once the CMake configuration is cleaned up, you can try using graphical effects through QtQuick like this:

import QtQuick 2.15
import QtQuick.Controls 2.15

Rectangle {
    width: 200
    height: 200
    color: "red"

    // Add graphical effects like DropShadow
    DropShadow {
        anchors.fill: parent
        horizontalOffset: 4
        verticalOffset: 4
        color: "black"
        radius: 10
    }
}

6. Summary of Actions to Take:

1. Verify the existence of QtGraphicalEffects in your Qt installation:

   • If not found, this suggests QtGraphicalEffects is not available or was integrated into QtQuick in Qt6.
   • Try installing or checking your Qt6 packages.

2. Remove QtGraphicalEffects from CMake:

   • For Qt6, graphical effects are generally integrated into QtQuick and you don't need a separate GraphicalEffects module.
   • Adjust your CMakeLists.txt to link only QtQuick and QtQuickControls2 as needed.

3. Use Graphical Effects Directly in QML:

   • Use built-in effects like DropShadow and Blur directly from QtQuick.

Let me know if this works or if the issue persists!

---

User:

Qt6 doc says GraphicalEffects exists only in Core5Compat.

ChatGPT:

Ah, thank you for that clarification! Yes, you're right, in Qt6, QtGraphicalEffects is indeed available only through the Qt5Compat module, which is intended for compatibility with Qt5-based functionality. This means if you want to use effects like DropShadow or Blur in Qt6, you'll need to use the Qt5Compat module, which provides backward compatibility for Qt5 features.

Steps to Fix the Issue

1. Ensure Core5Compat Module is Installed:
   First, make sure that the Core5Compat module is installed as part of your Qt6 installation. This module provides the backward compatibility layer for Qt5 features, including QtGraphicalEffects.

   On Ubuntu, you can install the necessary Qt5Compat module (if not installed already) using:

   sudo apt-get install qt6-core5compat
   

   If you installed Qt6 using the Qt Maintenance Tool, ensure that the Core5Compat component is selected during the installation.

2. Modify CMakeLists.txt to Include Core5Compat:
   Since QtGraphicalEffects is part of Core5Compat in Qt6, you need to update your CMakeLists.txt to include Core5Compat and link it properly

:

```cmake
find_package(Qt6 6.8.2 REQUIRED COMPONENTS Core Gui Qml Core5Compat QuickControls2)

target_link_libraries(your_target
    Qt6::Core
    Qt6::Gui
    Qt6::Qml
    Qt6::Core5Compat  # Ensure Core5Compat is linked for backward compatibility
    Qt6::QuickControls2
)
```

3. Use Qt5Compat.QtGraphicalEffects in Your QML:
   In your QML files, you should now import the Qt5Compat.QtGraphicalEffects module for access to the graphical effects:

   import QtQuick 2.15
   import QtQuick.Controls 2.15
   import Qt5Compat.QtGraphicalEffects 1.0  # Use the Core5Compat module for graphical effects
   
   Rectangle {
       width: 200
       height: 200
       color: "red"
   
       // Use effects from Core5Compat
       DropShadow {
           anchors.fill: parent
           horizontalOffset: 4
           verticalOffset: 4
           color: "black"
           radius: 10
       }
   }
   

Final Steps:

• Ensure you have the right module installed.
• Modify your CMakeLists.txt to include Qt6::Core5Compat.
• Update your QML imports to reference Qt5Compat.QtGraphicalEffects.

After this, you should be able to use graphical effects in your Qt6 project!

Let me know if you run into any further issues!

User said

works now with

import Qt5Compat.GraphicalEffects

ChatGPT said:

Awesome! I'm glad to hear it's working now with:

import Qt5Compat.GraphicalEffects

That was the key adjustment—using the correct import from the Qt5Compat module for GraphicalEffects. It allows you to use Qt5-style graphical effects like DropShadow, Blur, and others even in Qt6.

If you run into any more issues or need further assistance, feel free to reach out. Happy coding! 😊

[J.Hilk]

Compat modules are designed to ease developers transition from Qt5 Applications to Qt6.

There is no guarantee, how long they will be part of the Qt libraries.

Official support for Qt5 was dropped in 2023 and the commercial support for qt5 is stops this May (2025). I expect future releases to not have these modules.

So, keep that in mind.

[Aleksey_K]

@J-Hilk said in QML runtime error: module "Qt5Compat.QtGraphicalEffects" is not installed:

Compat modules are designed to ease developers transition from Qt5 Applications to Qt6.

There is no guarantee, how long they will be part of the Qt libraries.

Official support for Qt5 was dropped in 2023 and the commercial support for qt5 is stops this May (2025). I expect future releases to not have these modules.

So, keep that in mind.

Yep, probably need to remove it some day. Anyway ChatGPT tips for
import QtQuick.Controls.Styles -> QtQuick.Controls migration and Qt6::QuickControls2 component was useful. However any replacement for DropShadow?

[J.Hilk]

Not 1:1

From what I gathered when transitioning, was that you're supposed to use actual Shaders for it:
https://doc.qt.io/qt-6/qml-qtquick-shadereffect.html

Sadly delving into that, was for me a bit out of scope, for my projects. So I ended up with an offset rectangle filled black and semi transparent. "Good enough" for my use case.

[Aleksey_K]

@Aleksey_K said in QML runtime error: module "Qt5Compat.QtGraphicalEffects" is not installed:

However any replacement for DropShadow?

MultiEffect component seems allow 1:1: https://stackoverflow.com/a/77585865/630169

[Aleksey_K]

@J-Hilk MultiEffect replaces ColorOverlay as well:
https://stackoverflow.com/a/79205929/630169

[J.Hilk]

ah, a higher level API than working with shaders directly!

Didn't know it existed.

[Aleksey_K]

@J-Hilk said in QML runtime error: module "Qt5Compat.QtGraphicalEffects" is not installed:

ah, a higher level API than working with shaders directly!

Didn't know it existed.

Seems I saw this component when Qt6 appear, however further this migration info/links become lost, while current Qt/QML 6 migration docs are very poor and misses such info.

[JKSH]

@Aleksey_K said in QML runtime error: module "Qt5Compat.QtGraphicalEffects" is not installed:

@J-Hilk MultiEffect replaces ColorOverlay as well:
https://stackoverflow.com/a/79205929/630169

+1

@Aleksey_K said in QML runtime error: module "Qt5Compat.QtGraphicalEffects" is not installed:

However any replacement for DropShadow?

MultiEffect handles it, and there's also RectangularShadow now: https://doc.qt.io/qt-6/qml-qtquick-effects-rectangularshadow.html It doesn't support arbitrary shapes, but performs better than MultiEffect/DropShadow

@Aleksey_K said in QML runtime error: module "Qt5Compat.QtGraphicalEffects" is not installed:

migration info/links become lost, while current Qt/QML 6 migration docs are very poor and misses such info.

Agreed. Here's a request to improve things: https://bugreports.qt.io/browse/QTBUG-135865

[Aleksey_K]

Unfortunate MultiEffect is buggy comparing to ColorOverlay - it does not color my icon in some cases, so forced to rollback to Qt5Compat.GraphicalEffects.

[Aleksey Asensus]

@Aleksey_K said in QML runtime error: module "Qt5Compat.QtGraphicalEffects" is not installed:

Unfortunate MultiEffect is buggy comparing to ColorOverlay - it does not color my icon in some cases, so forced to rollback to Qt5Compat.GraphicalEffects.

Found solution for the full replacement: https://forum.qt.io/post/807844
Need to set brightness: 1.0, however now "transparent" color does not work if I need to keep original color unchanged, Probably need to add more complex logic to hide MultiEffect and show original Image.

So still on ColorOverlay.