I'm a bit confused about how to upgrade my HDF stack from 126.96.36.199 to the recent patch release 188.8.131.52.
The Ambari itself is already the latest version (2.5.1)
I've already upgraded the Management Pack on the Amabri server node to the latest version (184.108.40.206). But I don't see an entry for HDF-220.127.116.11 version from the dropdown list on the Admin -> Versions page.
How should I register the new version to be able to do this upgrade? Do I need to upload a "Version Definition File"?
The suggestions I had earlier to fix the version not appearing was when I performed an initial HDF install via Ambari not an upgrade.
I just attempted an upgrade from HDF 3.0.0 to HDF 18.104.22.168 and was able to reproduce your issue. When doing an upgrade you need to register the version you are upgrading to as described here:
Here is the basic process: