Hi!
It looks like you are trying to create an account on Indico. An Indico account is only required if you wish to submit a presentation for one of our upcoming workshops.
You do not need an Indico account simply to participate. If you wish to register as an attendee, please see the relevant Registration sub-page for the event you wish to attend.
Note that you may need to accept this more then once when creating an account. If you are unable to create an account please contact us.