Only way to get it working is to turn off remote firewall!
My second desktop computer this morning was updated with the spring creators update and immediately I lost multiplicity functionality. I could not get multiplicity on the primary PC to recognize the remote PC. I first uninstalled and then reinstalled multiplicity on the remote which did not help. Then, following some advice from Stardock, I disabled the Windows defender firewall on the remote PC and that worked. Then thinking everything was fine since primary was recognizing the remote, I turned the remote firewall back on and then again lost multiplicity functionality.
Is this an issue with the spring creators update and if so does multiplicity need to be updated?