https://github.com/ManageIQ/manageiq/pull/11773 has been backported
Fixed in 5.6.2.2.20161017185613_7cee0a0 Version 5.7.0.5 to 5.7.0.6 upgrade is not possible because of a bug in 5.7.0.5 where "Check Updates" button doesn't get active . This bug is fixed in 5.7.0.6