Hi, after upgrading to Ansible 2.2, I still have the problem, but now get a _much_ better error message: The Unix domain socket file name is too long.
It turns out that the generated socket name had 111 characters, due to a long, structured hostname, which includes the applications's and the client's name, amongst other things, which is a local standard I can't change. IOW, fixing this problem is an upstream issue, requiring a diffent socket naming scheme. Cheers, Toni