I followed the guide in the following link https://docs.wso2.com/display/IS500/WSO2+Identity+Server+as+an+OpenID+Provider I successfully added the certificate to the cacerts of Java but after restarting Liferay I got the same error from Liferay ("You have entered invalid data. Please try again") as when there was no certificate added. Note that I didn't deviate from the guide.
I've even tried to connect with a simple openid4java application and I get the following exception: org.openid4java.discovery.yadis.YadisException: 0x704: I/O transport error: peer not authenticated which according to most cases is because of SSL problems with the Java certificates.
Any ideas what might have gone wrong?