version 2.1.7

Can you use something like nmap on the machine running the main DCP-o-matic instance to see what ports are open on the server machines? Let me know if you need a walk-through. Did you turn off all firewalls to see if they are causing problems?

In firewall allowed both TCP and UDP connections to program (dcpomatic2_server.exe)
Which port must use dcpomatic_server? Netstat showed only one connection to remote host (where dcpomatic_server started), I am not sure it is it.

By default 6192 and 6193. Can you see what ports are open on the server machine from the master machine?

version 2.1.10 works fine on each machine, but only if running v2. If running both v1 & v2 - master machine has no connection to them :-/

As it stands there is no intention that v1 masters should work with v2 servers nor vice versa: it would be a lot of work. As long as v2 servers work ok with v2 clients, I'll close this. Thanks!