You may also see this errors before and frustrating how to fix this.

Response message: Error opening socket: PKIX path building failed: unable to find valid certification path to requested target

The idea is that you have to add the certificate to your java trusted store.

navigate to /bin in jmeter folder
edit and put in the location of your keystore.

# SSL properties (moved from
# Location of the truststore (trusted certificates)

But how can I get the jssecacerts (Keystore) ?

There’s a nifty tool from SUN (Oracle) called InstallCert, get it from here, with this tool you can install any certification from any website you want.
to install a certification or you could use the keytool to import the certificate (in der format)

“java InstallCert” or “keytool -import -file xxx.cer”

and hit enter.  InstallCert will generate keystore for you, that is, no more error

ps. with keytool the output file is located in a different name and folder.