500 error on all POST requests to `constituent/v1/constituents`

Pete H

I am getting a 500 error when adding constituents. Before the weekend the response was OK, now an error. Is this being looked into?

This is using Visual Studio 2022, C#, adapting the copperplate from SKI api. I am able to UPDATE other fields but this endpoint https://api.sky.blackbaud.com/constituent/v1/constituents is returning the 500 code (see below)

StatusCode: 500, ReasonPhrase: 'Internal Server Error', Version: 1.1, Content: System.Net.Http.HttpConnectionResponseContent, Headers:
{
Cache-Control: no-cache
Pragma: no-cache
Strict-Transport-Security: max-age=31536000;includeSubDomains
Content-Security-Policy: frame-ancestors 'self' https://host.nxt.blackbaud.com
X-Content-Type-Options: nosniff
section-io-id: 3a4bf2df38285ef25525318539bdc81b
Date: Mon, 08 Jun 2026 16:27:10 GMT
Content-Length: 36
Content-Type: application/json; charset=utf-8
Expires: -1
}, Trailing Headers:
{
}}