"unknown tag 28 encountered"

[bonsai]

I found the following REST-related error in the article below!

https://www.servicenow.com/community/sysadmin-forum/where-are-errors-logged-if-the-rest-api-returns-...

I found a REST-related error in the following article!

The error record contained the message "[ERROR CODE: -1] unknown tag 28 encountered".

The response status is "-1".

Normal response statuses are 200 or 201.

I don't understand the cause of this problem...

Is it an instance issue, or an issue outside the instance?

I'm looking for a solution.

Currently, I cannot reproduce this error, and the flow is working correctly.

This sudden error is a problem, and I need a solution.

[Kieran Anson]

Hi,

Is this an outbound REST call via a MID server using IntegrationHub? Have you reviewed the following KB article around OSCP checks?

https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB1001641 

[Tanushree Maiti]

Hi @bonsai 

As per Servicenow,

"The "unknown tag 28 encountered" error is because something unexpected came back when trying to establish a TLS connection. The reason that a TLS connection couldn't be established is the HTTP 503 (service unavailable) response from the endpoint server."

Check whether  Endpoint API host was available when the api ran.

This error indicates the issue is generally with the server's availability rather than a misconfiguration on the ServiceNow end.

[bonsai]

I'm not using a MID server.

If possible, please include the URL of the source!