Apple Certificate Revoked for SoapUI

Hello, 

I've recently tried to install SoapUI 5.7 however gatekeeper is blocking the application from running stating that the "App's Authorization has been revoked" by Apple. This also appears in versions 5.6.1 and 5.6.0 that we've tested (although we haven't tested any earlier versions from that).

What caused the revocation of the certificate by Apple?