jenkins - Jenkins Build Slave - 接続できません

Question

JNLP 経由でマスター Jenkins サーバーに接続したいのですが、常に次のエラーが発生します。

Failing to obtain https://<master-server>/buildserver/computer/CaptainBrowser/slave-agent.jnlp?encrypt=true
 java.io.IOException: https://<master-server>/buildserver/computer/CaptainBrowser/slave-agent.jnlp?encrypt=true doesn't look like a JNLP file; content type was text/html; charset=iso-8859-1
at hudson.remoting.Launcher.parseJnlpArguments(Launcher.java:306)
at hudson.remoting.Launcher.run(Launcher.java:219)
at hudson.remoting.Launcher.main(Launcher.java:192)