使用Klaxon和Anko的doAsync解析JSON失败

每当我按下按钮时,我都会尝试解析包含JSON的url:

    button.setOnClickListener {
doAsync{
    val result = URL("http://date.jsontest.com/").readText()
    val parser: Parser = Parser()
    val stringBuilder: StringBuilder = StringBuilder(result)
    val json: JsonObject = parser.parse(stringBuilder) as JsonObject
    val time = "Time : ${json.string("time")}"
uiThread { textView.setText(time) }}}

但我有一个错误:

修剪批准的打印服务时出错。java.util.concurrent。TimeoutException:无法获取后台处理程序!

怎么了?