
Keytool -importcert -file c:\yoursiteorHost.cer -keystore. Here is the command that worked successfully for importing the certificate into SoapUI (assuming your certificate called as yoursiteorHost.cer file is available on c:\ drive, see syntax below) It is important to import the certificate into the keystore of jre which comes with "SoapUI" and not the keystore of the jre/java that is on the host operating system.
DOWNLOAD SOAPUI 5.3.0 HOW TO
How to import Certificate into SoapUI Use the keytool command to import the CA certificate to the keystore of SoapUI. SoapUI SoapUI NetBeans Plugin SoapUI Maven Plugin SoapUI IntelliJ Plugin SoapUI Eclipse Plugin.
DOWNLOAD SOAPUI 5.3.0 UPGRADE
However, upgrade to 5.5.0 version resolved this issue as well. Looking for a previous version of SoapUI Open Source. The version 5.3.0 also had issue with importing of site certificate into SoapUI. Once upgrade is complete you will see new icon for 5.5.0 version. The old vmoptions will be removed and replaced with new vmoptions file. With an easy-to-use graphical interface, and enterprise-class features, SoapUI allows you to easily and rapidly create and execute automated functional, regression, compliance, and load tests. If you selected this option then you will have one instance of SoapUI. SoapUI is a free and open source cross-platform Functional Testing solution. Note: Select option to upgrade current directory instead of selecting new directory. The upgrade will take hardly 2 minutes to complete. Select upgrade current version and accept all defaults to keep it simple. Select "Check for updates" under the Help menu and you will get option for upgrade.

I had above issue as well as another issue reaching to https endpoint.

If you are on 5.3.0 better upgrade to 5.5.0 which is available now (Feb 2019). Update: Version 5.5.0 does not have this issue. The fix is to Enable TLS 1.2 protocol for SOAP/REST calls in SoapUI, by ammending the vmoptions file to add the directive for TLS as (=TLSv1.2).
