Step 1
File -> Preferences -> Proxy Settings set to None
Step 2
In my case the server were the service was installed was configured only for TLS. SSL was not allowed. So you have to update SoapUI vmoptions file by adding
-Dsoapui.https.protocols=TLSv1.2
You can find vmoptions file under SoapUI installation folder: C:\Program Files (x86)\SmartBear\SoapUI-5.0.0\bin\soapUI-5.0.0.vmoptions
OR change your server setting to allow SSL