@Eager, it worked for me. Thanks!

Hi,

I am not aware of any changes to the lookup of the the specifics files.
And everything you describe looks good.
Can you try to use the QML_IMPORT_PATH variable of qmake instead of the QML2_IMPORT_PATH environment variable?

I found a solution. I followed the below Steps:
1.Created a QtCreator Extension Plugin
2.In Pro file: Add
uri = mycompany.qmlcomponents
version =1.0

3.Added my CustomControl QML file.
4.Registered using qmlRegisterType
5.In qml dir:
module mycompany.qmlcomponents
plugin MyExtensionPlugin
classname MyExtensionPlugin
typeinfo mycompany.qmlcomponents
designersupported
5.Wrote the MetaInfo file (myextensionplugin.metainfo):
MetaInfo {
Type {
name: "mycompany.qmlcomponents.MyCustomItem"
icon: "images/customitem-icon.png"

ItemLibraryEntry { name: "CustomItem" category: "My Extension - Items" libraryIcon: "images/customitem-icon.png" version: "1.0" requiredImport: "mycompany.qmlcomponents" Property { name: "itemItext" type: "binding" value: "qsTr(\"Button\")" } } } }

6.Create a designer folder
7.Add following to designer.pri
QML_FILES +=
$$PWD/CustomItemSpecifics.qml
QML_FILES += $$PWD/myextensionplugin.metainfo
QML_FILES +=
$$PWD/images/customitem-icon.png
8.Build and install
9.Generate qmltypes: [You can also do this during qmake]
qmlplugindump mycompany.qmlcomponents1.0 > plugins.qmltypes
10.The controls will be available in the qml designer.

Check the unsupported properties for custom controls:
http://doc.qt.io/qtcreator/creator-quick-ui-forms.html