java.io.IOException: Unable to write on channel java.nio.channels.SocketChannel in Play Framework - web-services

Question

I'm trying to upload a byte array to a remote WS with multipart/form-data in play! framework using Scala. My code is:
//create byte array from file
val myFile = new File(pathName)
val in = new FileInputStream(myFile)
val myByteArray = new Array[Byte](audioFile.length.toInt)
in.read(audioByteArray)
in.close()
// create parts
val langPart = new StringPart("lang", "pt")
val taskPart = new StringPart("task","echo")
val audioPart = new ByteArrayPart("sbytes", "myFilename", myByteArray, "default/binary", "UTF-8")
val client: AsyncHttpClient = WS.client
val request = client.preparePost(RemoteWS)
.addHeader("Content-Type", "multipart/form-data")
.addBodyPart(audioPart)
.addBodyPart(taskPart)
.addBodyPart(langPart).build()
val result = Promise[Response]()
// execute request
client.executeRequest(request, new AsyncCompletionHandler[AHCResponse]{
override def onCompleted(response: AHCResponse): AHCResponse = {
result.success(Response(response))
response
}
override def onThrowable(t: Throwable) {
result.failure(t)
}
})
// handle async response
result.future.map(result =>{
Logger.debug("response: " + result.getAHCResponse.getResponseBody("UTF-8"))
})
Every time I execute this request, it throws this exception:
java.io.IOException: Unable to write on channel java.nio.channels.SocketChannel
The remote server is OK, I can make sucessfull requests using for example Postman.
I'm using Play Framework:
play 2.2.3 built with Scala 2.10.3 (running Java 1.8.0_05)
Version of AsyncHttpClient:
com.ning:async-http-client:1.7.18
Any help is welcome!