We've confirmed the cause and have deployed a stable solution. We will continue to serve manifests to all SDK versions.
Posted Apr 18, 2018 - 18:01 PDT
We believe we've identified the cause as an http2 header compression bug in the versions of okhttp included in SDK 19 and below.
Posted Apr 18, 2018 - 15:29 PDT
A recent configuration change in our front-tier web servers has been causing android apps made using SDK version 19 and earlier to crash on launch. This has now been fixed, though we are continuing to investigate the underlying cause.