WCF throws SfxServerDidNotReply Error

We are working on a Silverlight 4/5 application that talks to the server through a WCF NetTcp service hosted by a Windows service.

In some cases, we get the error SfxServerDidNotReply

This is barely documented on the internet. People who experienced the same error did not post any responses.

Here is MSDN Thread that doesn't provide an answer.

We can also find a link in this ServiceChannel.cs class . But this code seems to only throw an exception when the channel is twoway, which is not our case.

In addition, this error occurs on the client side, monitoring the server side of the service shows nothing.

Any idea? Are some WCF experts here?