Final Update: 09/03/2015 09:07 PM UTC
We have experienced an issue with CodePlex between 01.11 AM to 01.30 AM UTC on 03/07/2015. Customers would not have been able to access Codeplex during the outage window.
The issue has since been mitigated and DevOps teams are actively investigating to prevent any recurrence.
-MSDN Service Delivery Team