Does this mean, that I cant get this information from headers? I think so.
I have sence of this error already in dirty approach: I get it from small file size combined with “404 Not Found” in response contents, but I wished to make eror sense more stricted and generalized if it possible.
if error 0, then check the response for validity (which is simple as our responses are always structured messages so json / xml). if parsing throws exception scan for error code, if thats of interest at all, otherwise just let the user know that the operation isn’t possible at the time. (the majority of these errors that would end in there should never happen with software you still support cause you know when you moved a page and if the server does not respond, you also won’t get a 404 etc)