NodeBB Email Settings Page Causing Cloudflare 520 Error

[boyle-taylor@community.nodebb.org]

I'm experiencing an issue with my NodeBB v4.4.6 installation where accessing the Email Settings page in the Admin Control Panel results in a Cloudflare 520 error ("Web server is returning an unknown error").

Details:

NodeBB version: 4.4.6 (recently upgraded from 3.12.7)
Database: MongoDB (no authentication) ( i plan to do it later)
Web server: Running behind Cloudflare (nginx)
Error occurs only on the email settings page (/api/admin/settings/email)
Other admin pages work fine
What I've tried:

Installed nodebb-plugin-emailer-smtp
Disabled HTTP/2 to Origin in Cloudflare
Rebuilt and restarted NodeBB
Checked for errors in NodeBB logs (none visible)
I'm using Resend for email (have proper DNS records set up in cloudfare when I was testing Flarum forum) and need to configure NodeBB to use it. Any suggestions on how to fix this specific 520 error when accessing the email settings page?

[baris@community.nodebb.org]

Put some console.logs and see if the /admin/settings/email route is being called. https://github.com/NodeBB/NodeBB/blob/master/src/controllers/admin/settings.js#L116 this is the controller that gets called when you load that page.

Start nodebb with node app.js to see the logs and see what happens you load the page.

[boyle-taylor@community.nodebb.org]

Thanks baris for the debugging guidance. Here's what we've discovered through systematic testing:

What we tried:

Added console.log debugging to settings.js as suggested
Started NodeBB with node app.js to monitor logs
Key finding: Debug logs never appeared when accessing email settings
Infrastructure testing revealed:

Admin API endpoints work correctly: All /api/admin/* routes return proper 401 (auth required) responses
Email API specifically works: /api/admin/settings/email returns 401, not 520
JavaScript template fails: /assets/templates/admin/settings/email.js returns 520 error
Current plugin status:

2025-08-23T02:28:21.248Z [4567/298549] - error: [plugins/emailer-sendgrid] API key not set!
Infrastructure fixes attempted:

Disabled HTTP/2 to Origin in Cloudflare
Added extended timeouts (120s) and larger buffers (512k) for admin routes in Nginx
Added specific location blocks for /community/api/admin/ routes
Issue persists
Current assessment: The issue is NOT with the admin route itself (it returns proper 401) but with NodeBB's dynamic JavaScript template generation for /assets/templates/admin/settings/email.js. This suggests the email settings page template processing is failing during compilation, possibly due to the emailer plugin error.

Key question: Should the email settings page load even with a misconfigured emailer plugin, or is it expected that template generation would fail if the plugin has errors?

The admin API works fine - it's specifically the client-side template JavaScript that's failing with 520.

[baris@community.nodebb.org]

If the javascript template is failing to load you might need to run ./nodebb build so it is generated in the build folder. Check if it's in the folder build/public/templates/admin/settings

[boyle-taylor@community.nodebb.org]

I did that too before I posted the reply here. I think maybe it was a rule in nginx to disallow paths which had /email, that was the main culprit.

It was a fresh installation and I thought of installing the forum again. So I did it and its working now.

Thanks for your replies though. I understand as the co founder of this software, you must be a busy guy.

Love the software.