По ссылке и правда ничего нет, но только что проверил, что ядро 1.12.2 последнего билда (1620) успешно загружает ванильное ядро.
https://api.papermc.io/v2/projects/paper/versions/1.12.2/builds/1620/downloads/paper-1.12.2-1620.jar
Не работает, вот что пишет:
Downloading vanilla jar...
Failed to download vanilla jar
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 sun.net.
www.protocol.https.HttpsClient.afterConnect(Unknown Source)
at sun.net.
www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
at sun.net.
www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
at sun.net.
www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at sun.net.
www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
at java.net.URL.openStream(Unknown Source)
at io.papermc.paperclip.Paperclip.checkVanillaJar(Paperclip.java:191)
at io.papermc.paperclip.Paperclip.checkPaperJar(Paperclip.java:122)
at io.papermc.paperclip.Paperclip.setupEnv(Paperclip.java:95)
at io.papermc.paperclip.Paperclip.main(Paperclip.java:49)
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)
... 18 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)
... 24 more
