After installing Appian, we are using https and are able to use Appian, and Appi

After installing Appian, we are using https and are able to use Appian, and Appian is sending task emails successfully. However, when I try to reset a password for a user, I get the following error when it tries to send the email to the user. The full error is attached. Not sure why I am getting an SSL error on this transaction, everything else seems to work with https.

javax.resource.spi.work.WorkCompletedException: com.appiancorp.process.engine.EmailBodyException: Email body failed to render
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target...

PKIXPathBuildingError.txt

OriginalPostID-121826

OriginalPostID-121826