It's an SSL-related issue. It's not obvious what would cause it for that particular environment. How are your endpoints different? Please verify the protocol you should be using: http vs https. And are you running the tests from the SoapUI Pro GUI?
Each one of your HTTPS endpoints likely requires different SSL certificates. Currently, you SSL certificate should be defined in SoapUI Pro in: File > Preferences > SSL Settings.
Currently there is a limitation of specifying a single SSL cert in SoapUI Pro. There is a workaround provided for environments so that SSL certs can change dynamically. That workaround is described here: viewtopic.php?t=13014#p31789