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:
{
}}

Crystal Bruce

Hi @Pete H - checking in to see if you are still seeing this error? I'm also tagging @Erik Leaver in for awareness. Thanks!

Erik Leaver

Hi @Pete H

A 500 Internal Server Error from the SKY API /constituent/v1/constituents endpoint almost always indicates something went wrong on the server side—but in practice, it’s often triggered by a specific request condition.

Assuming the call hasn't changed at all check:

Pagination Issues: This endpoint enforces paging rules.

• limit too large (over allowed max, typically 5000 or lower depending on context)
• offset beyond dataset range

Throttling / Rate Limits: While typically a 429, in edge cases:

• High-volume calls can degrade into 500 responses
• Check your api usage

Data-Specific Edge Cases:

• Corrupt or incomplete records in the database
• Constituents with unusual data relationships
• Fields returning null where backend doesn’t expect it

You’ll often see:

• Works for most queries
• Fails only when hitting specific records

Debug Steps

1. Retry the same call
   • If intermittent it's potentially a backend timeout
2. Strip down the request
   • Remove all filters
   • GET /constituents?limit=1
   • If this works issue is likely in parameters/limits
3. Test in Postman vs. app
   1. Helps isolate whether it’s request construction vs. backend

If it continues, please log a case with support. Please include:

• Full request (headers + URL)
• Timestamp (with timezone)
• Correlation ID (from response headers)
• Whether it’s reproducible