Go to the “Edit” menu and choose “Options”. Here you can specify the X and Y size of the editor, so change them to something that will fit your screen. After changing them, close the edit window and restart the level editor.
Go to the “Edit” menu and choose “Options”. Here you can specify the X and Y size of the editor, so change them to something that will fit your screen. After changing them, close the edit window and restart the level editor.