Those sort of responses are typically "browser can not reach the application" errors ; the cause of that sort of error can be varied though and not really application-related (unless the application/webserver itself is "down" which would also report that sort of thing).
i.e. your local PC's network error, local-network error, your connection to the internet, CA's connection to the internet... and so on.
For diagnostics to work out who needs to fix things, you need to eliminate stuff ; can you get to any PPM services? can you get to CA's SAAS portal, can you get to Google, can you get to your local intranet, does your local network report any intermittent connectivity problems (obviously I'm trivialising a bit here, but have to narrow down the problem area)