Where did my material / texture buttons go? Something happened when editing a Blender scene that caused me to lose the whole texture properties window and most of the materials window as well. They all appear as normal when starting a new file, but for this file they seem to be permanently gone.

This is what the window looks like now:
When using the Cycles render engine, the textures tab will only show if you have a texture added to your material. 

If there's no texture properties, then you can enable it by assigning a texture of any kind to the color input of your shader.


Click the dot for the Color Input of your shader
Select a texture of any kind
The texture properties will now be shown