I'm currently developing my app to integrate with Yahoo OpenID. I have been noticing that many times, when I redirect the client to Yahoo's servers, Yahoo's webpages don't return. After thinking that I was doing something wrong, I tried another service (http://www.packagetrackr.com/) that works with Yahoo's OpenID, and it too displayed the same problems.
Any site throwing random errors doesn't give us any clue where it goes wrong because from Yahoo! OP's point of view, we already send the assertion back to the RP and we don't know how RP handles it and why it fails unless we are given more information from the RP.
Since you have control of your site, you can log more information to facilitate trouble-shooting. Once you see any such error happens, can you please tell us exactly what the error is and if possible the HTTP request and response parameters? That will be helpful.
I see you may have misunderstood me. It's not the site that gives the error. Rather, the connection fails _after_ the user is handed over to Yahoo's URL endpoints. I posted a simple video on Youtube (http://www.youtube.com/watch?v=MPuRxF5X3sA) to demonstrated the problem in action. As you may notice, the url I was at is the url for yahoo's servers...
As I've mentioned before, the problem is not exclusive to any specific website, and doesn't happen every time (which is why I suggested that you try to log in many times).
Thanks a lot for producing the demonstration video. I notice that this happens with the Google Chrome browser only. I have tried it and when I see the error happens, I just reload the page and then I can go through the flow successfully.
I've also tried with Firefox, IE and Opera and cannot reproduce this problem by repeately signing in, so I think it is most likely Google Chrome browser's issue only. I've also searched the Net and found that this type of error (Error 2 (net:ERR_FAILED): Unknown error.) has plagued users for a long time: http://code.google.com/p/chromium/issues/detail?id=89
Please let us know if you can reproduce this issue in non-Chrome browsers.
Especially important is at time 1:40 (direct link to 1:40) where it clearly fails while showing Yahoo's URL on top.
Also, when I "just reload the page" (in chrome) it actually partially breaks the flow. It will manage to transmit the OpenID login, but will fail to include the oAuth part of it [my application also asks for access to email]...
We think the SSL configuration issue has been fixed and we have put those boxes back to service. Please let us know if you see this issue again and if so can you please let us know roughly the time you see the problem and what your browser is.