There does not seem to be any problem with the drawing.  You need to pick up the rectangle by clicking on its outline.  You cannot pick it up by clicking inside the rectangle because Stardraw does not consider the filled area to be something that can be selected.  To drag a rectangle you must always click on a line (the outline) even if it is filled.

I hope this is helpful.

Thanks for your answer! Then it might be my computer that creates the problem because when you normally "pick" the rectangle it's 4 corner should be marked but this is not happening. It seems to mark the underneath laying line. After some struggling can i manage to pick the rectangle and edit it but It's not showing this on the rectangle. This is a little tricky to do so I'll try another computer to see if that helps. As a note: I can pick the "black fader" and thats is marked on my symbol. No problem there to edit.

Perhaps there are several objects that exactly overlap, e.g. a rectangle that covers 4 lines that are the exact size and position of the rectangle's outline.  This would certainly make it tricky to select things.  Perhaps you can delete the lines that lay underneath.

Thanks for your answer. Yes I'll will do that later on.

I noticed one thing, if i zoom out can i pick  the rectangle and it's corners also markes as it shall, no problem there but if i zoom in very much so i only have, say 2 rectangles in the window, then i get the problem, that it's not marks the corners when i pick on it.