Why when i try to change the size of gui object , object dissapear.
If you look in the properties view, the size of plate_1 is in hundreds of units. You are setting it to (1,2,1) so it’s likely it’s roughly a pixel large afterwards (almost invisible). Size is not the same as scale, the final size a node takes up on screen is size * scale. I think you want to do gui.set_scale instead of gui.set_size if you want it to grow relatively to the size.
Thank you so much. I understand that isnt neccesary using gui.set_size.