Folder already exists

To contain the images of my project, I created a folder with all of them. I dragged said folder to the project window, and the images loaded correctly in the application.
Later I deleted said folder and tried to drag a different folder to the project window, but the message appears.
It already exists! And it repeats with any folder I try to drag.

If I include the folder name in the manifest, they do appear when running in the browser, but not when compiling with Voltbuider.
Could it be an AppStudio bug? Or am I doing something wrong?
Thanks for the help.

There are two ways to add a folder to an AppStudio project.

  1. Using the finder, drag and drop the folder into the Project Explorer panel in AppStudio. The folder cannot be in your project already - it has to come from an outside directory. AppStudio will copy the folder to your project folder. (In your case, the folder is already there, which is why you get the message.)

  2. Add the folder name into extraFiles in Project Properties.

Ok, that was the problem, I took the folder out of the project folder, and I was able to drag it to the project window
Now everything works perfect.
The problem is that the help manuals are very short, and we get stuck in many steps.
Thanks for the help.