Photoshop: CS5 3D tool was working normally, the last two days the ''create'' button stopped working..whats wrong?

It might help if you gave us some details: OS, GPU, is your video card driver up to date, is Photoshop up to date, etc.

Generally the 3D and OpenGL drawing options fail because of bugs in the video card drivers.

Try this document: GPU and OpenGL support | Photoshop CS4, CS5: http://adobe.ly/OpenGL

Make sure that OpenGL Drawing is enabled and you have the latest and greatest video drivers directly from the ATI/AMD or nVidia manufacturers websites.