Thanks hansmex and Puybaret for your quick replies. That was very much appreciated.

Thanks a lot Puybaret, that was the answer: there was a tiny object somewhere far from the design. I deleted it and now the problem is solved.

Hello everyone,
I have a problem with the aerial view. I can see my design as a miniature in the background but I can't zoom in to display it in a normal size. I tried all buttons available. I can move the design but I can't zoom in to make it bigger.
Thanks for your help !
Regards
Thunder