I am also having the same issue. I have v9 B&R and One running on the same VM running Windows 2012 R2. The host is running VMware 5.5 Update 2 and the VM has 4 virtual CPUs, 8GB of memory and one VMXNET3 allocated. I have upgraded to v9 update 1 on both products. I can ping the server by name, but I went ahead and tried the IP and still received the same connect error. I tried shutting down the servers firewall, no go. Then I opened the servers VM console and tried to run the monitor right on the server and received the same connect error. I opened services and planned to restart the One monitor service, but it hung in a stopping state and I had to reboot. Once the server was back up the client was working again. This happened before, but I was getting ready to reboot the server anyway after performing Windows updates and when it worked after the reboot I just kinda forgot about it until today when it failed again.