C:/JDK8/bin/java.exe -jar BuildTools.jar --rev 1.8.8 

Attempting to build Minecraft with details: VersionInfo(minecraftVersion=1.8.8, accessTransforms=bukkit-1.8.8.at, classMappings=bukkit-1.8.8-cl.csrg, memberMappings=bukkit-1.8.8-members.csrg, packageMappings=package.srg, minecraftHash=a0671390aa0691e70a950155aab06ffb, classMapCommand=null, memberMapCommand=null, finalMapCommand=null, decompileCommand=null, serverUrl=null, mappingsUrl=null, spigotVersion=null, toolsVersion=0)
Starting download of https://s3.amazonaws.com/Minecraft.Download/versions/1.8.8/minecraft_server.1.8.8.jar
Exception in thread "main" java.io.FileNotFoundException: https://s3.amazonaws.com/Minecraft.Download/versions/1.8.8/minecraft_server.1.8.8.jar
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1898)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1500)
        at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:268)
        at java.net.URL.openStream(URL.java:1093)
        at com.google.common.io.Resources$UrlByteSource.openStream(Resources.java:72)
        at com.google.common.io.ByteSource.read(ByteSource.java:296)
        at com.google.common.io.Resources.toByteArray(Resources.java:98)
        at org.spigotmc.builder.Builder.download(Builder.java:1083)
        at org.spigotmc.builder.Builder.main(Builder.java:416)
        at org.spigotmc.builder.Bootstrap.main(Bootstrap.java:27) 

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(Alerts.java:192)
    at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1497)
    at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:212)
    at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979)
    at sun.security.ssl.Handshaker.process_record(Handshaker.java:914)
    at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:563)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1512)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1440)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254)
    at org.spigotmc.builder.Builder.get(Builder.java:802)
    at org.spigotmc.builder.Builder.startBuilder(Builder.java:252)
    at org.spigotmc.builder.Bootstrap.main(Bootstrap.java:60)
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(PKIXValidator.java:387)
    at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
    at sun.security.validator.Validator.validate(Validator.java:260)
    at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1479)
    ... 15 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:145)
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:131)
    at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382)
    ... 21 more