vertica-7.0.1 installation error

Hi 

I am new to HP vertica. Currently trying to setup the community edition vertica-7.0.1-0.x86_64.RHEL5.rpm on a centos 6.5 release of 3 nodes.  Unfortunately the installation has failed with the following error! 

Can someone help me quickly to solve this problem ?  

Thanks in  advance, 
Nishant

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>> Starting installation tasks.
>> Getting system information for cluster (this may take a while)...

Default shell on nodes:
172.22.225.151 /bin/bash
172.22.225.150 /bin/bash
172.22.225.149 /bin/bash

>> Validating software versions (rpm or deb)...


>> Beginning new cluster creation...

backing up admintools.conf on 172.22.225.149

>> Installing software (rpm or deb)...

Installing rpm on 2 hosts....
installing node....  172.22.225.150
Error: __exit__
Traceback (most recent call last):
  File "/opt/vertica/oss/python/lib/python2.7/site-packages/vertica/install/__init__.py", line 1065, in run_install
    _main(options)
  File "/opt/vertica/oss/python/lib/python2.7/site-packages/vertica/install/__init__.py", line 745, in _main
    install_error = SSH.installNode( installerSSH, host, options.rpm_file_name, running_as )
  File "/opt/vertica/oss/python/lib/python2.7/site-packages/vertica/network/SSH.py", line 1704, in installNode
    [ nodeHost ], DBinclude.rpmDestFile)
  File "/opt/vertica/oss/python/lib/python2.7/site-packages/vertica/network/adapterpool.py", line 283, in copyLocalFileToHosts
    with apool.setHosts(dest_hosts):
AttributeError: __exit__
Installation FAILED with errors.

****
AdminTools and your existing Vertica databases may be unavailable.
Investigate the above warnings/errors and re-run installation.

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