If you get this desktop error at startup:
...and the URL appears to be valid, it may be a name resolution issue. Try running ipconfig /flushdns from a command prompt to clear the DNS cache. If that doesn't help, in Desktop Login / Set Host Location, reference the server by IP instead of name, e.g. http://126.96.36.199/imis/CS instead of http://myserver/imis/CS.