What is likely the the issue here is that cloud v4 enforces the use of tls 1.2 which is badly supported by SoapUI.
You can edit the startup script of SoapUI to enforce the right java version but this gave me an annoying popup and loads of warnings so what i did instead to enable this in SoapUI is copy/paste the jre 1.8 folder into your SoapUI installation folder, this allows you to use tls 1.2.
e.g. copy C:\Program Files (x86)\Java\jre1.8.0_131 to C:\Program Files (x86)\SmartBear\SoapUI-5.3.0\jre
If you do this make sure that you copy the right bits version of java i.e. i use the 32 bits version of SoapUI so i also require a 32bits version of java.
*No guarantees that SoapUI will still work as before, but so far it seems to be okay for me.
I hit this problem too on using the V4 cloud.
I would have followed Pieter's advice but I am on 64-bit and the folders didn't correspond - and actually I'm out of my comfort zone chopping about runtime folders.
So I did some more googling and eventually came across this blog which gives an even simpler remedy that worked straightwaway for me: https://siking.wordpress.com/2016/02/18/another-way-to-fix-sslhandshakeexception-in-soapui/
All you have to do is rename the jre
folder in the SOAPUI programme directory to jre.ignore
so that it goes off and finds an uptodate version of the java libraries elsewhere in your system. And if it doesn't work it's very easy to revert.