This seems to be a dated known issue about the need to generate the certificates. You can find one of the blogs here <http://www.mkyong.com/webservices/jax-ws/suncertpathbuilderexception-unable-to-find-valid-certification-path-to-requested-target/> .
For further assistance I would recommend posting a question to StackOverflow (which we also monitor), as this falls outside the scope of Google Groups which is not meant for specific 1-on-1 technical issues but for general discussion of the platform and its services. Check out our community support page <https://cloud.google.com/support/docs/stackexchange> for the list of tags we monitor. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/d1732ed4-a920-49b2-8dea-1584310ceae8%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
