We have much improved the error handling in version 6 of the library. You now have synchronous exceptions if the error lies in the input parameters and dedicated listeners to detect issues related to an object event.

Also setting up the connection is much easier as you don't have to create/wait for the engine, you just create the client and ask to connect. We also removed the dependencies based on the "when" the various calls have to be made.

I strongly suggest to upgrade to the latest library, even more so if you are starting a new project.

You can find more information here:
Upgrade guide: http://blog.lightstreamer.com/2012/0...pt-client.html
Developer guide: http://www.lightstreamer.com/docs/cl...nt%20Guide.pdf
new API: http://www.lightstreamer.com/distros...nce/index.html
Changelog: http://www.lightstreamer.com/distros...TML#web_client

Also consider that the next version of Lightstreamer is expected before the end of January.