You have like this error when use java applet;
means java does not trust your root ca cert.
You can check java trust root ca cert this way;
password:changeit
C:\Program Files (x86)\Java\jre7\bin>keytool -list -v -keystore ../lib/security/cacerts > C:\export.txt
You can import your root ca cert this way;
password:changeit
C:\Program Files (x86)\Java\jre7\bin>keytool -import -alias customcacert -keystore ..\lib\security\cacerts -file C:\root.cer
New article https://docs.microsoft.com/en-us/azure/java-add-certificate-ca-store