module "QtQuick.Effects" is not installed - in Design mode of Qt Creator

[petero3]

Trying to preview blur or glow effects in Design mode of Qt Creator.
MultiEffect blur works when actually running the app, but in Design mode, I get the warning triangles: "module "QtQuick.Effects" is not installed" and "Item could not be created." And the effect is not visible.

Is MultiEffect not supported in Design mode?
If not, which blur/glow effects are supported in Design mode?

https://doc.qt.io/qt-6/qml-qtquick-effects-multieffect.html
No caveat mentioned here?

https://doc.qt.io/qtcreator/creator-quick-ui-forms.html
This says that Shader Effect component is not supported in UI files. But doesn't explicitly mention MultiEffect? Or explain why? Or give workarounds/alternatives?

import QtQuick
import QtQuick.Window
import QtQuick.Effects

Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")   

    Item {
        anchors.fill: parent

        Rectangle {
            id: myrect
            anchors.centerIn: parent
            width: 240
            height: 240
            color: "#ff0000"
        }

        MultiEffect {
            source: myrect
            anchors.fill: myrect
            blurEnabled: true
            blurMax: 64
            blur: 1.0
        }
    }
}

Thank you
-- Peter

Qt Creator 10.0.1
Based on Qt 6.4.3 (GCC 10.3.1 20210422 (Red Hat 10.3.1-1), x86_64)
Built on May 4 2023 01:14:39
From revision d2b3c31e04

Ubuntu 22.04.2 LTS
GNOME 42.5
Wayland

[petero3]

@petero3
PS. layer.samples also seems to work (for smoothing edges) at runtime, but not in Design mode of Qt Creator.

[petero3]

@petero3
README.txt
Known Issues in Qt Design Studio 4.1

• Effects not supported with Qt 6: Blend, InnerShadow, and all blur effects besides FastBlur (GaussianBlur, MaskedBlur, RecursiveBlur, DirectionalBlur, RadialBlur, ZoomBlur).

[petero3]

@petero3
MultiEffect blur works in Qt Design Studio 4.1.0, but not Design mode of Qt Creator 10.0.1.