On a brand-new Mac running OS 10.10, I'm getting the following message when starting KNIME 2.10.3. As I don't have this issue on my other machines running an older OS, I suspect the issue is OS-related.
Already known? If further details are required, let me know.
I have seen this before as well and we are investigating it. I believe it only happens if you have your wireless adapter on, and are not connected to the internet just fyi.
I also have to clarify the issue: It's nothing OS 10.10-specific, but also happened on my old machine. From my standpoint, I can confirm your statement, that it only seems to happen on WiFi connections, as I'm having no issues at the office via Ethernet cable.
Type the code bellow, it will show what is your current computer hostname.
hostname
Type the code bellow but replace the "computername" part with the name you want, just make sure it ends with ".local", it will ask for the password, don't forget to type it.
sudo scutil --set HostName computername.local
Done, just close and open Knime again, it will not show the error.