I'm summarising an earlier thread.
If a user failed to enter 'http://' at the beginning of a proxy server address, Logos crashes with no message, but with this error written to the Logos log. A crash log is created, but it's empty.
Unhandled exception: System.NotSupportedException: The ServicePointManager does not support proxies with the users_proxy_server scheme.
Rather than simply exiting Logos should either display a warning message, or silently add 'http://' to the beginning of the address.