Surfacing processing timeout error (#23586)

* Surfacing processing timeout error

* Update src/content/docs/images/reference/troubleshooting.mdx

Co-authored-by: Doug <[email protected]>

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Co-authored-by: Doug <[email protected]>

Author: 2 people

src/content/docs/images/reference/troubleshooting.mdx

@@ -43,6 +43,7 @@ When resizing fails, the response body contains an error message explaining the
 * 9524 — The `/cdn-cgi/image/` resizing service could not perform resizing. This may happen when an image URL is intercepted by a Worker. As an alternative you can [resize within the Worker](/images/transform-images/transform-via-workers/). This can also happen when using a `pages.dev` URL of a [Cloudflare Pages](/pages/) project. In that case, you can use a [Custom Domain](/pages/configuration/custom-domains/) instead.
 * 9520 — The image format is not supported. Refer to [Supported formats and limitations](/images/transform-images/) to learn about supported input and output formats.
 * 9522 — The image exceeded the processing limit. This may happen briefly after purging an entire zone or when files with very large dimensions are requested. If the problem persists, contact support.
+* 9529 - The image timed out while processing. This may happen when files with very large dimensions are requested or the server is overloaded. 
 * 9422, 9424, 9516, 9517, 9518, 9522 & 9523 — Internal errors. Please contact support if you encounter these errors.
 
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