Animation freezing?

I had my project working fine some days ago, today i opened it and my animations stopped working properly, when i play the scene, the animation freeze (i think) on the first frame, also a particle system that i have doesn't play too, and the animator tab freezes too, looking like this:

(the load bar is freezed as well) I'm a total newbie with unity so maybe this is just a simple configuration thing or something like that, thank you for your answers and sorry for the bad english.

Using unity 4.6