Now that's a brilliant error message!
Try it again, taking note of the time, and check the event logs on both the system you're running the desktop alert software on, and the primary polling engine in your SolarWinds environment. Remember to check the solarwinds.net logs on the poller, as well as the system/application logs.
Hopefully that'll give you more information to go on.
I checked the logs on both the local Machine and the server and nothing is showing up about it. I also tried another machine and I am getting the same error.
Have you tried running the desktop notification tool software as admin? UAC may be blocking it.
So here is an odd thing. I was pointing to the address of our Core Orion server and was getting the exception. I tried another IP address for our Orion Web server and it worked fine. Does the Desktop tool have to be point to the web server?
For logging to Orion with Desktop notification tool please use same address which you used in browser.
Http://Orionserver.mydomain.com (Server is running on default 80 port)
Http://Orionserver.mydomain.com:8787 (Server is running on 8787 port)
192.168.1.10 (server is running under 80 port)
192.168.1.10:8787 (server is running under 8787 port)
httpS://orionserver.mydomain.com (Server is running under HTTPS with default 443 port)
httpS://orionserver.mydomain.com:444 (Server is running under HTTPS under 444 port)
In HTTPS you have to have trusted certificate in client machine, that means in browser you have to have green flag when you accessing OrionServer.