Create a RadForm application project.
On the form place a radPopupEditor.
Place a radPopupContainer on the form.
Place a multiline radTextBox on the radPopupContainer.
Set radPopupEditor1.Visible = false in the RadForm's constructor.
When you run, the editor is not visible, but the radPopupContainer is visible.

If you skip step 5, the editor is visible and the container is not visible until you click on the editor...as it should be.

If you have a program that later makes the editor visible, when you click the editor, the container will move from it's original location to under the editor.  Clicking the editor again hides the container, and the visibility of both seem to work correctly after that point.