My API's PATCH returns "400 Bad Request" when Cloudflare Proxy is on

General
1

Hello!

I’ve deployed an API application with GET, POST, PATCH methods allowed. But when I use PATCH with Cloudflare proxy enabled I have “400 bad request” with this response body: “\r\n400 Bad Request\r\n\r\n

400 Bad Request

\r\n
cloudflare\r\n\r\n\r\n”. This looks like Cloudflare append this error before API.

If I disable Cloudflare proxy on my domain/A record, PATCH is working.
What can I do?

Thanks.

3

Hello!

I’ve deployed an API application with GET, POST, PATCH methods allowed. .
But when I use PATCH with Cloudflare proxy enabled I have “400 bad request” with this response body:

“\r\n400 Bad Request\r\n\r\n400 Bad Request\r\n—cloudflare\r\n\r\n\r\n”. This looks like Cloudflare append this error before API.

If I disable Cloudflare proxy on my domain/A record, PATCH is working.
What can I do?

Thanks.

5

Hi @juliangorge,

If the error is returned by Cloudflare, then it means our Edge cannot route the request.

You will need to troubleshoot the request to see what is causing Cloudflare to reject your PATCH.
Support may be able to help if you are on Enterprise (Premium) with Edge tracing/logs.

Do open a ticket if you are on Enterprise (Premium) Support account.

Thank you.

7

Hello!
Can i open a ticker for this with Pro plan?

8

Hi @juliangorge,

Support generally does not troubleshoot bad requests.
User → Request → 400 [Cloudflare] → Request is dropped.

Since the request is never really routed, getting logs for this is difficult.
You may have a better chance of finding the issue with your request by trial and error.

Thank you.