Hi Andrés,
I just tried it and it seems to be working fine.  Maybe when you got those messages, the web service at NBCR was temporarily down… in that case, there is nothing that you (or we) can do, other than downloading and installing AutoDock Vina on your own computer and running it locally.  There is a "download" link at the AutoDock Vina website:
<http://vina.scripps.edu/>
You can specify running locally in the Chimera AutoDock Vina tool, in the "Executable location" section near the bottom of the dialog.
Best,
Elaine
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Elaine C. Meng, Ph.D.
UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab
Department of Pharmaceutical Chemistry
University of California, San Francisco

On Jul 23, 2013, at 7:51 AM, felipe vasquez <anfelvas@gmail.com> wrote:

> I am trying to perform a docking process via the tool 'autodock vina' embedded into chimera menu. However, once I am baout to run the process, I always obtain the same message:
>
> Service 'opal:vina_1.1.2' is unavailable.
>
> What can I do in order to overcome this problem? Thanks in advance for your help.