Dragging an extension to the working area results in Internal Error

[Mohamed_Tamer]

You can see this guide as well:

How to use extensions

How to use extensions? We frequently see users on the community who don’t know how to use extensions. This is from the App Inventor website Extension components can be used in building projects, just like other components. The difference is that extension components can be distributed on the Web and loaded into App Inventor dynamically: they do not have to be built into the App Inventor system, and they can be imported into projects as needed. With extensions, the range of App Inventor ap…