This is a specialized piece of software and we are always prioritizing state-of-the-art features over making it easier for unexperienced users to deal with it. Anyway, if you got here it means that you are too, for now, looking at future network technologies and should be familiar with the concepts and specs. If you are not, we recommend that you first attend a few tutorials on IMS, Linux administration and C/Java programming; or you could hire somebody (from our community for example) to do the job for you.

Most importantly: DO NOT FILL A BUG REPORT IMMEDIATELY!
Second most importantly: DO NOT EVEN THINK ABOUT POSTING SUPPORT REQUESTS IN THE ISSUE TRACKER! The request will be closed. Use the issue tracker only for outstanding bugs that have been discussed and accepted. Think that you might have just mis configured something and you will get your answer quicker and easier by asking on the appropriate mailing-lists.

When in trouble, you should, in this order:
1. Always read the FAQ. There is big probability that you did something wrong and the answer might be just there.

The target of the whole project is experimental. As such, we love logging because we want to know what happens. The CSCFs might print a lot of those. You can, of course, at any time change the logging level from the configuration file (the debug parameter).

Are you sure that you have changed all the configuration files? Grep for the old domain name.

Have you changed the s_cscf table in the icscf database? It contains the list of all your S-CSCFs.

Check the imsu table in the hss_db database. It might be that you have IMS Subscriptions that were left as registered in the old S-CSCFs and now the HSS/I-CSCF are trying to redirect you there. Clear the values in there.

You have probably forgot to add privileges for the user, that you are trying to register with, to perform authentication with the algorithm of your choice. In most cases you switched the authentication method in the S-CSCF but you did not allow the user to use anything else than AKAv1-MD5.

This error might also indicate that you are trying to use an authentication scheme not supported by the HSS in use. Please check that the authentication scheme is supported.