Connection error during installing vdp

hello all

i faced problem during install vdp.t he error is this: the connection test did not complete successfully.modify your network setting for vcenter credential
i add new user to my domain and give administrator  permission in vcenter but again same problem
i use vdp@vspher.local and vsphere.local@vdp and also for my domain too
i have no dns problem also
my vdp version is 6.1.11
my vcenter version is 7