Error message asterisk: outbound proxy URI '' is not valid

Ladies and gentlemen,

I try to register a trunk with the information T-Online provided.
But I get only the follwing errors:

[2017-01-29 18:33:06] ERROR[1716]: res_pjsip.c:3239 create_out_of_dialog_request: Unable to apply outbound proxy on request OPTIONS to endpoint 01 as outbound proxy URI ‘’ is not valid
[2017-01-29 18:33:06] ERROR[1716]: res_pjsip/pjsip_options.c:427 qualify_contact: Unable to create request to qualify contact sip:[email protected]:5060

I disabled SIP and use only PJSIP.

Hopefully someone can give me hint…



Did you ever find a solution to this issue? I am facing the same problem.