Initial Update: Monday, 1 August 2016 20:06 UTC
We are actively investigating issues with packaging service where a subset of customers using the Nuget restore build task, attempting to restore packages from a Visual Studio Team Services package source will experience intermittent exceptions of type “Unable to find version xx of package aaa”
We are working to resolve this issue and apologize for any inconvenience.
Sincerely,
Manjunath