You can get more details here : http://community.qlik.com/message/85314#85314
But I believe you would need session cals or an information access server ( not user or document cals)
Then, the option at QEMC->System->Setup->Qlikview server->Security->authentication client option into "Allow anonymous" or "Always anonymous" would work
I'm sorry but I can't read the infromation on the error box. One thing I forgot to point out is you have to have session Cals to do this. User Cals can't be anonymous.
Check you license and see if you have any session Cals