How to solve this error?

File “/usr/local/lib/python2.7/dist-packages/pkg_resources/”, line 870, in resolve
raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The ‘bench’ distribution was not found and is required by the application

When installing app on site that time this error will occur
Can any one help me how resolved this error???

Please go through following post