Between 01:00 AM 7/13 UTC and 06:30 PM 7/13 UTC most customers were not able to create a Azure AD B2C directory in the Azure Portal. The issue has been mitigated and customers are able to create new B2C directories now.
The error was "Unable to complete due to service connection error, please try again later".
We apologize for the inconvenience and are taking necessary steps to prevent future reoccurrence. There was no impact on existing B2C directories management and authentication scenarios.