Why is wagn-dev gem breaking my instance?+issues

I am trying to install Wagn on apache with phusionpasenger.

 

I am getting the message

 

Further information about the error may have been written to the application's log file. Please check it in order to analyse the problem.

Error message: The path `/......./ruby/gems/gems/wagn-dev` does not exist. (Bundler::PathError) Exception class: PhusionPassenger::UnknownError

I didn't think that wagn-dev was required.

What am I doing wrong?

Thanks,

Karl