Mask marquee is not visible in Photo Paint. Mask -> Mask Marquee menu item is checked and Mask -> Mask overlay menu item is unchecked. The software is in default state after installation. Where is the problem ? How can I display mask marquee ? I was accustomed from another graphic programs like MS Paint or GIMP that selected area of image is indicated by dashed line. Not so in Photo Paint.
Does your file have multiple objects?
No.