CORS headers not working only in Firefox

Question

I'm having problems only on Mozilla Firefox, my requests are "Unavailable (503)" because of the missing header Access-Control-Allow-Origin.

However, the header is on the server side, inside my web.config:

<system.webServer>
<httpProtocol>
   <customHeaders>
    <add name="Access-Control-Allow-Origin" value="*" />
    <add name="Access-Control-Allow-Headers" value="Origin, X-Requested-With, Content-Type, Accept, Authorization" />
    <add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE, OPTIONS" />
  </customHeaders>

This is the error (translated from spanish):

Request from another blocked source: the same source policy: http: // XXXXX (reason: missing CORS 'Access-Control-Allow-Origin' header).

The problem does not happen on IE and Chrome. Any clues?

Thank you all!

please post the full response - you might want to check the iis logs — Daniel A. White, Feb 24 '17 at 14:13
HTTP status codes and cross-origin related errors are unrelated. If you're get a 50x error, then you need to look at your server logs to find out what the error message actually is. — Quentin, Feb 24 '17 at 14:13
@DanielA.White I know, but that's the error I'm having. Edited answer. Thanks — GermanCH, Feb 24 '17 at 14:16
Note that getting a 50x error will likely cause the CORS headers to not be sent *as a side effect* resulting in an access control error message on the client. You still need to look at the server logs and identify the underlying cause of the 50x error. — Quentin, Feb 24 '17 at 14:17

score 0 · Accepted Answer · answered Feb 24 '17 at 14:24

0

Found the problem, maybe this could help someone:

On the request uris I was using the server name instead of the IP. IE and Chrome were able to resolve this, Mozilla wasn't.

I don't know how is this a problem for Mozilla anyway.

Thank you all

answered Feb 24 '17 at 14:24

GermanCH

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CORS headers not working only in Firefox

1 Answers1