Intermittently, over the past two days, two different LinkedIn "apps" have started to receive 999 Request Denied errors. Along with this, I receive: "reason-code=1,2,1" as a header. Specifically, this has been captured from the 3rd step of the oAuth process (communicating with https://www.linkedin.com/uas/oauth2/accessToken) - however making POST requests to the sharing endpoint also fails, but I've not yet captured the HTTP response code and data for those failures.
These two apps are the live and test sites for the same platform, running off different servers, different IP addresses, different client ids, and the two apps are tied to two different users (though I'm an admin on both). One thing they do have in common, is that they are both hosted on Linode.
Locally, (with a different client id/app) the integrations work without problems. If I use the test app client id locally (with the callback URLs added) the integration works without issues.
This seems to be intermittent. Over the past two days, there has been a high failure rate of POST requests to the API. And also intermittent complaints of performing an oAuth connection failing.
From the Developer website, I see the apps are well within their usage allowance.
Does anyone know what this particular error with reason code 1,2,1 refers to? The LinkedIn developer website has reference to the 999 error, but it seems to be restricted such that only registered members of the partner program can access them. And, is there any approach for preventing this error. Some other questions indicate that the 999 response code has started to come about through LinkedIn blocking various cloud providers, however that doesn't seem to explain why this is intermittent.
来源：https://stackoverflow.com/questions/33422904/intermittently-receiving-999-request-denied-from-the-linkedin-api-what-does-rea