Shading problem

So i’m new to blender and I have created an object with a plane and a light.
I have added shading to it and it worked fine.
I opened it back up the next day and when i run the game, the object is completely white. I’ve tried opening it up in different modes and draw types and nothing works.
Does anyone know how to fix this?

Sounds like you have UV unwrapped your object, have the display set to Multitextured (Properties panel under shading) but do not have an image assigned in the UV/image editor.
Change the view to Solid mode (3d view header) or change the shading from Multitextured to GLSL.