upstream sent invalid status "-1 Copy failed" while reading response header from upstream

[Maxim Dounin]

Hello!

On Sat, Oct 25, 2014 at 09:21:49PM -0400, NaZz wrote:

> I have a joomla website and when I am trying to update a larger extension I
> get bad gateway (502) error.
> I am able to update all small (normal) extensions.
> 
> I am getting this error in nginx error log:  "upstream sent invalid status
> "-1 Copy failed" while reading response header from upstream"

The message suggests your upstream server returned an invalid 
response, with "-1 Copy failed" in it instead of a valid HTTP 
status.  You have to dig into your upstream server to find out 
what goes on there.

-- 
Maxim Dounin
http://nginx.org/