using Apple as client

I normally use a linux workstation as my client with the downloaded binaries for the linux machine.

Now I would like to use my Apple as the client with the Apple binaries. I have a choice
ParaView-5.4.1-Qt5-OpenGL2-MPI-OSX10.8-64bit.dmg
ParaView-5.4.1-Qt5-OpenGL2-MPI-OSX10.8-64bit.unsigned.dmg
Which should I download?
I downloaded ParaView-5.4.1-Qt5-OpenGL2-MPI-OSX10.8-64bit.dmg
and I get this error when Iconnect
socket error permission denied
I follow the same procedure as I used successfully with linux, this is my first experience with Apple client. Any ideas as to the problem?

I assume you are trying to connect to a pvserver on a remote machine? Which executable gives you the error? The mac client?