Are you using remoting with .NET? If so you could get a .NET head to step through the code as the call is made. I've seen methods that throw errors fail silently and not return a result. If not are you making these calls consecutively? Can you replace the service calls to simple echo services and get it to work?

We use OpenAMF and Tomcat at my office, and we view the console as it plays out on-screen to see what we are sending and receiving. I do NOT know how to or if Remoting makes a log other than pushing items to the Tomcat log. We've never used it if it does create one.

But seeing as you need to find out what's going on, the first thing I would attempt is to isolate the call to the server. See if making the call from outside your code still gets you nothing.

If that doesn't work, see if there may be something wrong with any objects that are getting sent. Remoting may be choking on the data, but for whatever reason, it may not be able to send a Error object to you. Try not sending any object, sending a string, then getting more complex from there.

Are you testing with Flash Player 8.5? I've had a problem in that after a remote method throw an exception, calling the same method again will result in a packet of 0 length being sent and the call just "hangs."

So, check the content length and make sure it's greater than 0? Switching back to Flash Player 8 may fix it...

If you're using .NET try to delete the automatic generated service dlls files on the Flash Remoting directory.