Unable to connect with AWS S3 bucket using Ansible s3 module

I am trying to just get the objects from my AWS S3 bucket as follows:

- s3: bucket=killswitch object=/my/desired/key.txt dest=/usr/local/myfile.txt mode=get

but i am getting this error:

failed: [localhost] => {"failed": true, "parsed": false}
Traceback (most recent call last):
  File "/home/ubuntu/.ansible/tmp/ansible-tmp-1440571450.96-113302306180168/s3", line 2299, in <module>
    main()
  File "/home/ubuntu/.ansible/tmp/ansible-tmp-1440571450.96-113302306180168/s3", line 351, in main
    bucketrtn = bucket_check(module, s3, bucket)
  File "/home/ubuntu/.ansible/tmp/ansible-tmp-1440571450.96-113302306180168/s3", line 162, in bucket_check
    except s3.provider.storage_response_error, e:
AttributeError: 'NoneType' object has no attribute 'provider'


FATAL: all hosts have already failed -- aborting

what am i doing wrong ?