SSL Error? with Windows 10 / FMP 15.3 / Java 8u121

[RJS-IT]

We have been using 360Works Email 2 plugin, Version: 2.17 successfully for about a year now.  I have been diligently upgrading our PC's with the latest Filemaker Pro (15.3) and Java (8u121).   (from FMP 15.1 and Java 8u111)

Our Windows 7's PC's have been updated and after a restart work as normal.

Unfortunately we have some Windows 10 PC's and they are unwilling to play nice any more.  I have tried uninstalling/reinstalling versions of Java/FMP to no avail.  Is anyone able to save me from reinstalling these PC's?

Below example log event:

CONFIG: === Executing plugin function EmailConnectSMTP on thread main ===
Mar 27, 2017 2:08:53 PM com.prosc.emailplugin.EmailerModel connectSMTP
INFO: Auto-closing SMTP connection which was opened previously
Mar 27, 2017 2:08:53 PM com.prosc.emailplugin.EmailerModel connectSMTP
INFO: Connecting to SMTP server mailserver.address.com, username [email protected], port=465
Mar 27, 2017 2:08:53 PM com.prosc.fmkit.Plugin setLastError
SEVERE: PluginFunction PluginFunction{name='EmailConnectSMTP', functionID=-24868, minArgs=1, maxArgs=-1} got an error with converted args [mailserver.address.com:465, [ssl=1, timeout=9], null, null]
javax.mail.MessagingException: Could not connect to SMTP host: mailserver.address.com, port: 465;
  nested exception is:
    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
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2055)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:697)
    at javax.mail.Service.connect(Service.java:364)
    at com.prosc.emailplugin.EmailerModel.connectSMTP(EmailerModel.java:141)
    at com.prosc.emailplugin.EmailerPlugin.EmailConnectSMTP(EmailerPlugin.java:1786)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.prosc.fmkit.StaticFunction.invoke(StaticFunction.java:231)
    at com.prosc.fmkit.Plugin.invokeFunction(Plugin.java:352)
    at com.prosc.fmkit.RegisterablePlugin.invokeFunction(RegisterablePlugin.java:170)
    at com.prosc.fmkit.Plugin.invokeFunctionNoErrors(Plugin.java:333)
    at com.prosc.fmkit.PluginBridge$4.run(PluginBridge.java:1203)
    at com.prosc.fmkit.PluginBridge.runTask(PluginBridge.java:1443)
    at com.prosc.fmkit.PluginBridge.doFunction(PluginBridge.java:1220)
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
    at sun.security.ssl.Alerts.getSSLException(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
    at sun.security.ssl.Handshaker.processLoop(Unknown Source)
    at sun.security.ssl.Handshaker.process_record(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:543)
    at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:348)
    at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:236)
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2019)
    ... 15 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.validator.PKIXValidator.doBuild(Unknown Source)
    at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
    at sun.security.validator.Validator.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
    ... 27 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
    at java.security.cert.CertPathBuilder.build(Unknown Source)
    ... 33 more

Mar 27, 2017 2:08:53 PM com.prosc.fmkit.PluginBridge$4 run
CONFIG: === Executing plugin function EmailLastError on thread main ===
Mar 27, 2017 2:18:26 PM com.prosc.fmkit.PluginBridge$4 run
CONFIG: === Executing plugin function EmailConnectSMTP on thread main ===
Mar 27, 2017 2:18:26 PM com.prosc.emailplugin.EmailerModel connectSMTP
INFO: Auto-closing SMTP connection which was opened previously
Mar 27, 2017 2:18:26 PM com.prosc.emailplugin.EmailerModel connectSMTP
INFO: Connecting to SMTP server mailserver.domain.com, username [email protected], port=465
Mar 27, 2017 2:18:27 PM com.prosc.fmkit.Plugin setLastError
SEVERE: PluginFunction PluginFunction{name='EmailConnectSMTP', functionID=-24868, minArgs=1, maxArgs=-1} got an error with converted args [mailserver.domain.com:465, [ssl=1, timeout=9], null, null]
javax.mail.MessagingException: Could not connect to SMTP host: mailserver.domain.com, port: 465;
  nested exception is:
    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
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2055)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:697)
    at javax.mail.Service.connect(Service.java:364)
    at com.prosc.emailplugin.EmailerModel.connectSMTP(EmailerModel.java:141)
    at com.prosc.emailplugin.EmailerPlugin.EmailConnectSMTP(EmailerPlugin.java:1786)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.prosc.fmkit.StaticFunction.invoke(StaticFunction.java:231)
    at com.prosc.fmkit.Plugin.invokeFunction(Plugin.java:352)
    at com.prosc.fmkit.RegisterablePlugin.invokeFunction(RegisterablePlugin.java:170)
    at com.prosc.fmkit.Plugin.invokeFunctionNoErrors(Plugin.java:333)
    at com.prosc.fmkit.PluginBridge$4.run(PluginBridge.java:1203)
    at com.prosc.fmkit.PluginBridge.runTask(PluginBridge.java:1443)
    at com.prosc.fmkit.PluginBridge.doFunction(PluginBridge.java:1220)
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
    at sun.security.ssl.Alerts.getSSLException(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
    at sun.security.ssl.Handshaker.processLoop(Unknown Source)
    at sun.security.ssl.Handshaker.process_record(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:543)
    at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:348)
    at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:236)
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2019)
    ... 15 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.validator.PKIXValidator.doBuild(Unknown Source)
    at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
    at sun.security.validator.Validator.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
    ... 27 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
    at java.security.cert.CertPathBuilder.build(Unknown Source)
    ... 33 more

Mar 27, 2017 2:18:27 PM com.prosc.fmkit.PluginBridge$4 run
CONFIG: === Executing plugin function EmailLastError on thread main ===

[ryan360Works]

HI RJS-IT,

The error you are getting means that Java cannot complete the SSL handshake because the mail server you are trying to connect to either has a self-signed certificate or the certificate it has is not part of the Java trust store. Try adding the "forceTrust=true" parameter to the EmailConnectSMTP function call. This should force Java to trust the SMTP server's certificate and complete the SSL handshake. 

[RJS-IT]

Thank you, service restored!