Hello All,
Sorry about the lack of an update on Friday.
To answer a few questions, this is not related to a periodic refresh
of the Sandbox accounts. There should also not be a connection between
the version of a client library you're using and whether you have
trouble logging in or not.
Not all accounts are affected (the initial account I tried with was
not), but we're not sure at the moment why some accounts are having
issues logging in and others are not. The issue does seem to lie with
the code that talks to the Google Account service, and the core
engineering team is examining whether there are any recent changes to
the version of that service that the Sandbox speaks to that might
explain this behavior.
It's being actively investigated, and I'll let folks know when
there's an update.
Cheers,
-Jeff Posnick, AdWords API Team