This is the important part of the error message.
Caused by: com.mendix.systemwideinterfaces.MendixRuntimeException: java.security.PrivilegedActionException: javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
It means your computer can’t validate the SSL certificate on the REST service you are calling. If it works when deployed to the Cloud but not locally, that would suggest your local truststore doesn’t have the correct certificates. Are you up to date with all your Windows updates locally?