[17:17:58] [Craft Scheduler Thread - 5/WARN]: [PacketListenerApi] Failed to get resource info from spiget.org
java.net.ConnectException: Connection timed out: connect
        at java.net.DualStackPlainSocketImpl.connect0(Native Method) ~[?:1.8.0_91]
        at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source) ~[?:1.8.0_91]
        at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source) ~[?:1.8.0_91]
        at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source) ~[?:1.8.0_91]
        at java.net.AbstractPlainSocketImpl.connect(Unknown Source) ~[?:1.8.0_91]
        at java.net.PlainSocketImpl.connect(Unknown Source) ~[?:1.8.0_91]
        at java.net.SocksSocketImpl.connect(Unknown Source) ~[?:1.8.0_91]
        at java.net.Socket.connect(Unknown Source) ~[?:1.8.0_91]
        at sun.security.ssl.SSLSocketImpl.connect(Unknown Source) ~[?:1.8.0_91]
        at sun.security.ssl.BaseSSLSocketImpl.connect(Unknown Source) ~[?:1.8.0_91]
        at sun.net.NetworkClient.doConnect(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.http.HttpClient.openServer(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.http.HttpClient.openServer(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.protocol.https.HttpsClient.<init>(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.protocol.https.HttpsClient.New(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.protocol.https.AbstractDeleg ... on.getNewHttpClient(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) ~[?:1.8.0_91]
        at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source) ~[?:1.8.0_91]
        at org.inventivetalent.update.spiget.SpigetUpdateAbstract$1.run(SpigetUpdateAbstract.java:92) [PacketListenerAPI_v3.7.5-SNAPSHOT.jar:?]
        at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:71) [spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53) [spigot-1.8.8.jar:git-Spigot-21fe707-e1ebe52]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_91]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_91]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_91]

PacketListenerApi这个插件连不上spiget.org这个网站

他为什么要连接这个网站

发送服务器数据，这是个服务器各类信息数据库网站

不让他发送会发生啥呢

不知道，但你不写插件大概也无法阻止它发送，除非那个网站不在线或者你的服务器不接入互联网

啥叫不写插件

就是适用于mc服务器的java插件，可以通过代码限制网络连接

PacketListenerApi插件从远程服务器获取信息失败，有可能是插件自动更新