Using the official SLES 12 AWS AMI (e.g. in eu-central-1: ami-c425e4ab) I can't see the SLES12 repositories.

Digging further, I see the following under /var/log/cloudregister:

Code:
2017-02-13 08:30:02,549 INFO:Using API: regionInfo
2017-02-13 08:30:02,550 INFO:Using region server: 50.17.208.31
2017-02-13 08:30:02,554 INFO:Starting new HTTPS connection (1): 50.17.208.31
2017-02-13 08:30:18,106 ERROR:No response from: 50.17.208.31
2017-02-13 08:30:18,106 INFO:Using region server: 54.247.166.75
2017-02-13 08:30:18,107 INFO:Starting new HTTPS connection (1): 54.247.166.75
2017-02-13 08:30:33,200 ERROR:No response from: 54.247.166.75
2017-02-13 08:30:33,200 INFO:Using region server: 54.244.244.107
2017-02-13 08:30:33,201 INFO:Starting new HTTPS connection (1): 54.244.244.107
2017-02-13 08:30:48,696 ERROR:No response from: 54.244.244.107
2017-02-13 08:30:48,696 INFO:Using region server: 54.253.118.149
2017-02-13 08:30:48,697 INFO:Starting new HTTPS connection (1): 54.253.118.149
2017-02-13 08:31:04,651 ERROR:No response from: 54.253.118.149
2017-02-13 08:31:04,651 ERROR:None of the servers responded
2017-02-13 08:31:04,651 ERROR:	Attempted: ['50.17.208.31', '54.247.166.75', '54.244.244.107', '54.253.118.149']
2017-02-13 08:31:04,651 ERROR:Exiting without registration
I tried to re-trigger `registercloudguest` and see the following errors:

Code:
ip-172-31-7-8:~ # /usr/sbin/registercloudguest --force-new
/usr/lib/python2.7/site-packages/requests/packages/urllib3/connection.py:264: SubjectAltNameWarning: Certificate for 54.244.244.107 has no `subjectAltName`, falling back to check for a `commonName` for now. This feature is being removed by major browsers and deprecated by RFC 2818. (See https://github.com/shazow/urllib3/issues/497 for details.)
  SubjectAltNameWarning
/usr/lib/python2.7/site-packages/requests/packages/urllib3/connection.py:264: SubjectAltNameWarning: Certificate for 50.17.208.31 has no `subjectAltName`, falling back to check for a `commonName` for now. This feature is being removed by major browsers and deprecated by RFC 2818. (See https://github.com/shazow/urllib3/issues/497 for details.)
  SubjectAltNameWarning
/usr/lib/python2.7/site-packages/requests/packages/urllib3/connection.py:264: SubjectAltNameWarning: Certificate for 54.247.166.75 has no `subjectAltName`, falling back to check for a `commonName` for now. This feature is being removed by major browsers and deprecated by RFC 2818. (See https://github.com/shazow/urllib3/issues/497 for details.)
  SubjectAltNameWarning
/usr/lib/python2.7/site-packages/requests/packages/urllib3/connection.py:264: SubjectAltNameWarning: Certificate for 54.253.118.149 has no `subjectAltName`, falling back to check for a `commonName` for now. This feature is being removed by major browsers and deprecated by RFC 2818. (See https://github.com/shazow/urllib3/issues/497 for details.)
  SubjectAltNameWarning
Launching instances (and getting registered correctly) used to work a few weeks ago.

Is some wrong with the registration servers?

I tried the same process in us-east-1 without luck and also with an older AMI.