Why can't I add a new host to RHEV-M after updating RHEV-M to a newer version?

Issue

• After updating RHEV-M to a newer version, when I try to add a new host I get the following error message and the host is not added:

Host hostname installation failed. Please refer to /var/log/ovirt-engine/engine.log and log logs under /var/log/ovirt-engine/host-deploy/ for further details.

• File /var/log/ovirt-engine/host-deploy/ovirt-host-deploy-YYYYMMDDHHMMSS-xxxxxx.log shows the following error:

2015-08-05 16:33:29 DEBUG otopi.context context._executeMethod:152 method exception
Traceback (most recent call last):
  File "/tmp/ovirt-1Jfylb05O0/pythonlib/otopi/context.py", line 142, in _executeMethod
    method['method']()
  File "/tmp/ovirt-1Jfylb05O0/otopi-plugins/otopi/dialog/cli.py", line 147, in _customize
    "\nCustomization phase, use 'install' to proceed\nCOMMAND> "
  File "/tmp/ovirt-1Jfylb05O0/otopi-plugins/otopi/dialog/cli.py", line 102, in _runCommandPrompt
    prompt=True,
  File "/tmp/ovirt-1Jfylb05O0/otopi-plugins/otopi/dialog/machine.py", line 162, in queryString
    value = self._readline()
  File "/tmp/ovirt-1Jfylb05O0/pythonlib/otopi/dialog.py", line 259, in _readline
    raise IOError(_('End of file'))
IOError: End of file
2015-08-05 16:33:29 ERROR otopi.context context._executeMethod:161 Failed to execute stage 'Environment customization': End of file