Can not communicate with a new secondary machine

Trying to set up a new secondary machine with an older version of Multiplicity.  Here is the error I get. Aftyer setting up the software on on the new secondary machine and trying to locate it on the network with the primary machine, it can not find it and I need to enter manually. Different IP address on the primary machine 10.0.0.150. When I check network settings on the new secondary machine, it shows an IP address as shown 10.0.0.37 for its connection to the same wireless network as the primary machine. Can anyone help? I had this working nicely with the former secondary machine with no issues until this change.