The list of modpacks could not be downloaded

[lemmings189]

Hello,
When I launch the launcher, 3 error windows shows:

To report this error, please provide:

java.io.IOException: The list of modpacks could not be downloaded.
	at com.skcraft.launcher.InstanceList$Enumerator.call(InstanceList.java:191)
	at com.skcraft.launcher.InstanceList$Enumerator.call(InstanceList.java:102)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.ssl.Alert.createSSLException(Unknown Source)
	at sun.security.ssl.TransportContext.fatal(Unknown Source)
	at sun.security.ssl.TransportContext.fatal(Unknown Source)
	at sun.security.ssl.TransportContext.fatal(Unknown Source)
	at sun.security.ssl.CertificateMessage$T13CertificateConsumer.checkServerCerts(Unknown Source)
	at sun.security.ssl.CertificateMessage$T13CertificateConsumer.onConsumeCertificate(Unknown Source)
	at sun.security.ssl.CertificateMessage$T13CertificateConsumer.consume(Unknown Source)
	at sun.security.ssl.SSLHandshake.consume(Unknown Source)
	at sun.security.ssl.HandshakeContext.dispatch(Unknown Source)
	at sun.security.ssl.HandshakeContext.dispatch(Unknown Source)
	at sun.security.ssl.TransportContext.dispatch(Unknown Source)
	at sun.security.ssl.SSLTransport.decode(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.decode(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.readHandshakeRecord(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
	at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
	at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
	at com.skcraft.launcher.util.HttpRequest.runRequest(HttpRequest.java:160)
	at com.skcraft.launcher.util.HttpRequest.execute(HttpRequest.java:118)
	at com.skcraft.launcher.InstanceList$Enumerator.call(InstanceList.java:138)
	... 5 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)
	... 23 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)
	... 29 more

To report this error, please provide:

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.Alert.createSSLException(Unknown Source)
	at sun.security.ssl.TransportContext.fatal(Unknown Source)
	at sun.security.ssl.TransportContext.fatal(Unknown Source)
	at sun.security.ssl.TransportContext.fatal(Unknown Source)
	at sun.security.ssl.CertificateMessage$T13CertificateConsumer.checkServerCerts(Unknown Source)
	at sun.security.ssl.CertificateMessage$T13CertificateConsumer.onConsumeCertificate(Unknown Source)
	at sun.security.ssl.CertificateMessage$T13CertificateConsumer.consume(Unknown Source)
	at sun.security.ssl.SSLHandshake.consume(Unknown Source)
	at sun.security.ssl.HandshakeContext.dispatch(Unknown Source)
	at sun.security.ssl.HandshakeContext.dispatch(Unknown Source)
	at sun.security.ssl.TransportContext.dispatch(Unknown Source)
	at sun.security.ssl.SSLTransport.decode(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.decode(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.readHandshakeRecord(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
	at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
	at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
	at com.skcraft.launcher.util.HttpRequest.runRequest(HttpRequest.java:160)
	at com.skcraft.launcher.util.HttpRequest.execute(HttpRequest.java:118)
	at com.skcraft.launcher.selfupdate.UpdateChecker.call(UpdateChecker.java:40)
	at com.skcraft.launcher.selfupdate.UpdateChecker.call(UpdateChecker.java:23)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)
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)
	... 23 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)
	... 29 more

To report this error, please provide:

java.io.IOException: The list of modpacks could not be downloaded.
	at com.skcraft.launcher.InstanceList$Enumerator.call(InstanceList.java:191)
	at com.skcraft.launcher.InstanceList$Enumerator.call(InstanceList.java:102)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.ssl.Alert.createSSLException(Unknown Source)
	at sun.security.ssl.TransportContext.fatal(Unknown Source)
	at sun.security.ssl.TransportContext.fatal(Unknown Source)
	at sun.security.ssl.TransportContext.fatal(Unknown Source)
	at sun.security.ssl.CertificateMessage$T13CertificateConsumer.checkServerCerts(Unknown Source)
	at sun.security.ssl.CertificateMessage$T13CertificateConsumer.onConsumeCertificate(Unknown Source)
	at sun.security.ssl.CertificateMessage$T13CertificateConsumer.consume(Unknown Source)
	at sun.security.ssl.SSLHandshake.consume(Unknown Source)
	at sun.security.ssl.HandshakeContext.dispatch(Unknown Source)
	at sun.security.ssl.HandshakeContext.dispatch(Unknown Source)
	at sun.security.ssl.TransportContext.dispatch(Unknown Source)
	at sun.security.ssl.SSLTransport.decode(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.decode(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.readHandshakeRecord(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
	at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
	at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
	at com.skcraft.launcher.util.HttpRequest.runRequest(HttpRequest.java:160)
	at com.skcraft.launcher.util.HttpRequest.execute(HttpRequest.java:118)
	at com.skcraft.launcher.InstanceList$Enumerator.call(InstanceList.java:138)
	... 5 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)
	... 23 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)
	... 29 more

And the launcher window says: Failed to fetch page: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Does anyone has a solution ?
Thanks a lot

[lemmings189]

Do I need to add this: -Djavax.net.debug=SSL ?
But where ?
https://stackoverflow.com/questions/6908948/java-sun-security-provider-certpath-suncertpathbuilderexception-unable-to-find

[hedgehog1029]

Your server certificates may be invalid, or may be invalid in the eyes of java SSL - it has its own certificate store in some cases, so very new certificates (like modern Let's Encrypt) can be regarded as invalid. Check your Java installs and make sure they're all up to date.