422 Unprocessable Entity when clicking on "Show full Post" in Discourse post

I’m really hoping I can get some help here. Browsed the web, but couldn’t fine a case matching mine.

I’m testing Wordpress with Discourse. Separately they both work just fine. However I’ve got an issue when using the WP plugin.
When I publish a WP post, a topic gets created in Discourse using the plugin as desired. The topic itself is created correctly. However when I click the “Show full Post” button the WP post doesn’t get expanded.
In the browser console I see an error like this:

Request URL: http://forum.sadzinica.pl/posts/19/expand-embed
Request Method: GET
Status Code: 422 Unprocessable Entity
Remote Address:
Referrer Policy: strict-origin-when-cross-origin
Cache-Control: no-cache, no-store
Connection: keep-alive
Content-Type: application/json; charset=utf-8
Date: Tue, 12 Jan 2021 09:07:49 GMT
Referrer-Policy: strict-origin-when-cross-origin
Server: nginx/1.14.2
Set-Cookie: __profilin=REMOVED; path=/; HttpOnly; SameSite=Lax
Transfer-Encoding: chunked
X-Content-Type-Options: nosniff
X-Discourse-Route: posts/expand_embed
X-Discourse-Username: admin
X-Download-Options: noopen
X-Frame-Options: SAMEORIGIN
X-Permitted-Cross-Domain-Policies: none
X-Request-Id: b904c2d5-2088-4193-be0c-f36b497d716e
X-Runtime: 0.021514
X-XSS-Protection: 1; mode=block
Accept: application/json, text/javascript, */*; q=0.01
Accept-Encoding: gzip, deflate
Accept-Language: pl-PL,pl;q=0.9,en-GB;q=0.8,en;q=0.7,de-DE;q=0.6,de;q=0.5,en-US;q=0.4,it;q=0.3,es;q=0.2,ro;q=0.1,it-IT;q=0.1
Connection: keep-alive
Cookie: __profilin=REMOVED; _t=REMOVED; _forum_session=I-REMOVED-IT
Discourse-Logged-In: true
Discourse-Present: true
Discourse-Track-View: true
Host: forum.sadzinica.pl
Referer: http://forum.sadzinica.pl/t/zebranie-wiejskie-w-sprawie-x/15/3
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36
X-CSRF-Token: 1ke5PaosmJ5gYeRpUs6ZkMWD+H4zaovMmVr3JPPNXeuidSmhdD2FmkeBaTgrH0TUuU+GrH/+OV0c338W/4RbjA==
X-Requested-With: XMLHttpRequest

And a jquery error:

XMLHttpRequest.send | @ | includes.js?v=10da95…f1bd50fe50ed714:819
  | send | @ | _ember_jquery-189e46…649161a18d.js:10113
  | ajax | @ | _ember_jquery-189e46…6649161a18d.js:9696
  | i | @ | _application-525b557…c2ebdfb8509.js:9229
  | (anonymous) | @ | _ember_jquery-189e46…649161a18d.js:72238
  | n | @ | _ember_jquery-189e46…649161a18d.js:72760
  | i | @ | _application-525b557…c2ebdfb8509.js:9242
  | expand | @ | _application-525b557…2ebdfb8509.js:16991
  | expandFirstPost | @ | _application-525b557…2ebdfb8509.js:78560
  | (anonymous) | @ | _application-525b557…2ebdfb8509.js:82798
  | value | @ | _application-525b557…2ebdfb8509.js:82756
  | value | @ | _application-525b557…2ebdfb8509.js:82794
  | click | @ | _application-525b557…2ebdfb8509.js:78431
  | (anonymous) | @ | _application-525b557…2ebdfb8509.js:75834
  | (anonymous) | @ | _application-525b557…2ebdfb8509.js:75733
  | value | @ | _application-525b557…2ebdfb8509.js:82756
  | k | @ | _application-525b557…2ebdfb8509.js:75732
  | (anonymous) | @ | _application-525b557…2ebdfb8509.js:75833
  | dispatch | @ | _ember_jquery-189e46…6649161a18d.js:5443
  | d.handle | @ | _ember_jquery-189e46…6649161a18d.js:5247

My setup: WP and DIscourse installed inside Ubuntu 20.04 LTS VM running on Virualbox under Linux. I’m testing withinmy local network with my own DNS directing to the host hosting the Virtualbox VM. I use 2 nginx reverse proxies. The first one in Ubuntu VM redirects requests to/from VM docker containers ports/unix sockets
Then this is forwared by Virtualbox to port 8000 on the host and then another nginx does reverse proxy to map this to port 80 of the host machine (host hosting the VM).
I’m testing this to simulate a real setup as I want to run both Wordpress and Discourse inside a VPS when I get everything working locally.

Please let me know if you need more info. Thank you!

Hey there @dgtal1 apologies for the slow reply here. Are you still experiencing this issue? Also, was it just this specific post, or all posts?

I suspect this one has something to do with the content of the wordpress post itself, which seems to be initiating a request.

Sorry to bump an old post, but I’m having this issue as well, on Drupal though – not WordPress. I had previously disabled Content Security Policy to try and fix this issue, but now I see the 422 Unprocessable Entity when clicking the Show Full Post button. This broken button functionality seems to be happening across all articles that have been posted, so not just new ones. Older ones with truncation enabled are also affected.

My install is behind Cloudflare, but I’m not seeing any security event logs that indicate resources are being blocked from the WAF area or managed rules. I’m really not sure what to do next to fix this.

Hey there @spectrum, would you mind opening a separate support topic with some further details including

  1. Some logs (like the first post in this topic).
  2. Links to the relevant posts on Discourse and Drupal if possible.

Not all 422 errors are the same. In the above case it was likely due to the content of the post.

*Note that I moved your post to support from wordpress as this is not about Wordpress or the WP Discourse plugin.

1 Like

Is this the same issue that’s been resolved in this topic @spectrum?


Yes it is! Apologies for my delay. I was able to confirm this is working after an IP address was unblocked from our server. I had forgotten I’d reached out on this thread too while troubleshooting so sorry about that! Hopefully this helps point others with similar issues in the right direction.