Warning flood with skyboxes?

adding a skybox works as described in https://wiki.jmonkeyengine.org/legacy/doku.php/jme3:advanced:sky

However I must be missing a step as when I esc out i get a flood of near system crashing popup windows complaining about something to do with frame-buffer?!

Has any one else run into this?

never mind , seems I was pushing for a fullscreen mode my computer didn’t like