Modify Yellow Dotted Line in GIMP

How do I remove or resize the marching ants from around the apple? It appeared when I used the move tool to move the position of the apple. It is in its own layer. I need to modify the image/layer outside that boundary but I am not allowed. I have tried select none. According to the select menu there is nothing selected. I'm a Photoshop user, but I'm trying to learn GIMP in order to teach my programing students how to illustrate games in a software that does not cost an arm & a leg, and is available in Linux.