POST to /fmeapiv4/ldapservers/{id}/synchronize returns 204 with empty body — FME marks it as "rejected / translation failed"

Hi ​@carolina_w,

Sorry to hear you’re running into this issue! I’m not overly familiar with the OpenAPICaller transformer, but is an empty response body what you are expecting with this request? Does the request you’re making seem to be working as it should apart from this?

Depending on your needs and how you have this set up, you could change the workspace settings to continue running even when a rejected feature is encountered (e.g. this 204/No Content response). This can be done in Workbench in the Navigator window (‘Workspace Parameters’ > ‘Log and Troubleshoot’ > ‘Rejected Feature Handling’).

Let me know if I’m misunderstanding your question, or if you have anything else to share that might help me understand your workflow a bit better!

-  Aaron H.

Thanks for the reply!

Yes — in this case a 204 No Content response is exactly what the FME Server REST API is supposed to return. According to FME’s Swagger definition, the /ldapservers/{id}/synchronize endpoint returns 204 when the synchronization request is accepted. The API call itself is working correctly.
 

I did enable the Rejected Feature Handling option as you suggested, and with that setting the workspace runs as expected. However, it still feels like FME shouldn’t treat a valid 204 response as an error in the first place. The same thing happens with the standard HTTPCaller, which also rejects the feature on a 204.

So everything is functioning on the server side, but the rejection behavior in the callers seems a bit like a bug or at least unexpected handling of 204 responses.

Hi ​@carolina_w,

I’ve tried to reproduce this behaviour in both 2024 and 2025, and unfortunately I’ve been unsuccessful. I’ve tried multiple endpoints that return a 204 (No Content) response, and each time the response is routed to the Output port (not Rejected) using the HTTPCaller.

In order to see why your workspace is handling the 204 response this way, I would suggest submitting a support ticket with us. In your ticket, if you could include the description of the issue (as you have above), as well as the workspace, that would be great.

Looking forward to helping you resolve this!

- Aaron H.