I checked every combination of good and bad values and always got the correct response, including subscription id itself being verified. This is fixed. Tested on 5.6.1.0.20160726144018_810a94f using https://10.16.7.93/ems_cloud/
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://rhn.redhat.com/errata/RHSA-2016-1634.html