Pmpro_signup is not working

Hi,

the following shortcode used:
[pmpro_signup]

The form filled in. Next step is Membership checkout. Membership level chosen (ID:1), account information added. No price is for this level.
Username, pswrd, email address confirmed with more information. No registration form changed. Terms and condition accepted. Than the following message received:
This membership level is restricted to certain users only. Make sure you are logged into your existing account and using the proper username.

The registration checked and no datas are in PmPro Dashboard member section.

Please, advise.

Thanks.

L