"PKIX path validation failed" is seen in the eMessage Connector log file when connecting to ThingWorx Platform

ERROR c.t.p.e.EmessageRequestContext - converter=EgressConverter contextId=79627: failure occurred: failureMessage=Unbind Request Failure
java.util.concurrent.CompletionException: com.thingworx.fabric.PlatformNotConnectedException: Unable to forward message. Platform or network unavailable or too busy
    at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:331)
    at java.base/java.util.concurrent.CompletableFuture.uniApplyNow(CompletableFuture.java:670)
    at java.base/java.util.concurrent.CompletableFuture.uniApplyStage(CompletableFuture.java:658)
    ...
Caused by: com.thingworx.fabric.PlatformNotConnectedException: Unable to forward message. Platform or network unavailable or too busy
    at com.thingworx.fabric.impl.AbstractManyPlatformWebSocketFabric.getChannel(AbstractManyPlatformWebSocketFabric.java:591)
    at com.thingworx.fabric.impl.AbstractManyPlatformWebSocketFabric.send(AbstractManyPlatformWebSocketFabric.java:451)
    at com.thingworx.sdk.impl.protocol.DefaultMessageChannel.send(DefaultMessageChannel.java:132)
    ... 36 common frames omitted
WARN  c.t.s.i.t.netty.NettyChannelHandler - [ClientHandler: 228d47af] SSLHandshake Exception, websocket not created:
javax.net.ssl.SSLHandshakeException: PKIX path validation failed: java.security.cert.CertPathValidatorException: validity check failed
    at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:131)
    at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:349)
    at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:292)
    ...
Caused by: sun.security.validator.ValidatorException: PKIX path validation failed: java.security.cert.CertPathValidatorException: validity check failed
    at java.base/sun.security.validator.PKIXValidator.doValidate(PKIXValidator.java:369)
    at java.base/sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:263)
    at java.base/sun.security.validator.Validator.validate(Validator.java:264)
    ...
Caused by: java.security.cert.CertPathValidatorException: validity check failed
    at java.base/sun.security.provider.certpath.PKIXMasterCertPathValidator.validate(PKIXMasterCertPathValidator.java:135)
    at java.base/sun.security.provider.certpath.PKIXCertPathValidator.validate(PKIXCertPathValidator.java:224)
    at java.base/sun.security.provider.certpath.PKIXCertPathValidator.validate(PKIXCertPathValidator.java:144)
    ...
<Validation Failure Reason>
    at java.base/sun.security.x509.CertificateValidity.valid(CertificateValidity.java:277)
    at java.base/sun.security.x509.X509CertImpl.checkValidity(X509CertImpl.java:675)
    at java.base/sun.security.provider.certpath.BasicChecker.verifyValidity(BasicChecker.java:190)
    ...