Error messages in nextcloud log

User Support
1

I struggled for about 3 days until I installed and ran nextcloud 32 and COOLWSD 25.04.7.1 on private subdomains behind a reverse proxy server.
Now everything seems to work (documents open in nextcloud and I can edit them).
However, I have a lot of these entries in the nextcloud log. Every time I open an office document, a new error appears in the log. However, I cannot say that the error message only occurs after opening an office document.

All errors are caused by the richdocuments application

{"reqId":"UPPS6pZwh9EyEW6tmJmK","level":3,"time":"2025-11-09T15:27:43+00:00","remoteAddr":"10.10.8.3","user":"admin","app":"richdocuments","method":"GET","url":"/index.php/core/preview?fileId=58&x=32&y=32&mimeFallback=true&v=0220e2&a=0","message":"Failed to convert preview: Client error: `POST https://collabora.example.com/cool/convert-to/png` resulted in a `413 Request Entity Too Large` response:\n<html>\r\n<head><title>413 Request Entity Too Large</title></head>\r\n<body>\r\n<center><h1>413 Request Entity Too Large</h1>< (truncated...)\n","userAgent":"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36","version":"32.0.1.2","exception":{"Exception":"GuzzleHttp\\Exception\\ClientException","Message":"Client error: `POST https://collabora.example.com/cool/convert-to/png` resulted in a `413 Request Entity Too Large` response:\n<html>\r\n<head><title>413 Request Entity Too Large</title></head>\r\n<body>\r\n<center><h1>413 Request Entity Too Large</h1>< (truncated...)\n","Code":413,"Trace":[{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/guzzle/src/Middleware.php","line":72,"function":"create","class":"GuzzleHttp\\Exception\\RequestException","type":"::","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/promises/src/Promise.php","line":209,"function":"{closure:{closure:{closure:GuzzleHttp\\Middleware::httpErrors():60}:61}:67}","class":"GuzzleHttp\\Middleware","type":"::","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/promises/src/Promise.php","line":158,"function":"callHandler","class":"GuzzleHttp\\Promise\\Promise","type":"::"},{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/promises/src/TaskQueue.php","line":52,"function":"{closure:GuzzleHttp\\Promise\\Promise::settle():156}","class":"GuzzleHttp\\Promise\\Promise","type":"::","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/promises/src/Promise.php","line":251,"function":"run","class":"GuzzleHttp\\Promise\\TaskQueue","type":"->"},{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/promises/src/Promise.php","line":227,"function":"invokeWaitFn","class":"GuzzleHttp\\Promise\\Promise","type":"->"},{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/promises/src/Promise.php","line":272,"function":"waitIfPending","class":"GuzzleHttp\\Promise\\Promise","type":"->"},{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/promises/src/Promise.php","line":229,"function":"invokeWaitList","class":"GuzzleHttp\\Promise\\Promise","type":"->"},{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/promises/src/Promise.php","line":69,"function":"waitIfPending","class":"GuzzleHttp\\Promise\\Promise","type":"->"},{"file":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/guzzle/src/Client.php","line":189,"function":"wait","class":"GuzzleHttp\\Promise\\Promise","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/Http/Client/Client.php","line":277,"function":"request","class":"GuzzleHttp\\Client","type":"->"},{"file":"/var/www/html/nextcloud.example.com/apps/richdocuments/lib/Service/RemoteService.php","line":94,"function":"post","class":"OC\\Http\\Client\\Client","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/nextcloud.example.com/apps/richdocuments/lib/Service/RemoteService.php","line":68,"function":"convertTo","class":"OCA\\Richdocuments\\Service\\RemoteService","type":"->"},{"file":"/var/www/html/nextcloud.example.com/apps/richdocuments/lib/Preview/Office.php","line":43,"function":"convertFileTo","class":"OCA\\Richdocuments\\Service\\RemoteService","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/Preview/GeneratorHelper.php","line":45,"function":"getThumbnail","class":"OCA\\Richdocuments\\Preview\\Office","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/Preview/Generator.php","line":342,"function":"getThumbnail","class":"OC\\Preview\\GeneratorHelper","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/Preview/Generator.php","line":313,"function":"generateProviderPreview","class":"OC\\Preview\\Generator","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/Preview/Generator.php","line":117,"function":"getMaxPreview","class":"OC\\Preview\\Generator","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/Preview/Generator.php","line":87,"function":"generatePreviews","class":"OC\\Preview\\Generator","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/PreviewManager.php","line":161,"function":"getPreview","class":"OC\\Preview\\Generator","type":"->"},{"file":"/var/www/html/nextcloud.example.com/core/Controller/PreviewController.php","line":166,"function":"getPreview","class":"OC\\PreviewManager","type":"->"},{"file":"/var/www/html/nextcloud.example.com/core/Controller/PreviewController.php","line":128,"function":"fetchPreview","class":"OC\\Core\\Controller\\PreviewController","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/AppFramework/Http/Dispatcher.php","line":204,"function":"getPreviewByFileId","class":"OC\\Core\\Controller\\PreviewController","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/AppFramework/Http/Dispatcher.php","line":118,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/AppFramework/App.php","line":153,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/var/www/html/nextcloud.example.com/lib/private/Route/Router.php","line":321,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/var/www/html/nextcloud.example.com/lib/base.php","line":1061,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/var/www/html/nextcloud.example.com/index.php","line":25,"function":"handleRequest","class":"OC","type":"::"}],"File":"/var/www/html/nextcloud.example.com/3rdparty/guzzlehttp/guzzle/src/Exception/RequestException.php","Line":111,"message":"Failed to convert preview: Client error: `POST https://collabora.example.com/cool/convert-to/png` resulted in a `413 Request Entity Too Large` response:\n<html>\r\n<head><title>413 Request Entity Too Large</title></head>\r\n<body>\r\n<center><h1>413 Request Entity Too Large</h1>< (truncated...)\n","exception":{},"CustomMessage":"Failed to convert preview: Client error: `POST https://collabora.example.com/cool/convert-to/png` resulted in a `413 Request Entity Too Large` response:\n<html>\r\n<head><title>413 Request Entity Too Large</title></head>\r\n<body>\r\n<center><h1>413 Request Entity Too Large</h1>< (truncated...)\n"}}

error
error2226Ă—809 277 KB

2

hii @gusto

Your log clearly shows that Nextcloud’s richdocuments app is trying to generate a preview thumbnail for an Office document by calling Collabora’s /cool/convert-to/png endpoint, but the request is too large for your reverse proxy or Collabora front-end to accept, leading to 413 Request Entity Too Large.

Root cause

This is not a problem in Nextcloud or Collabora themselves, but in your reverse proxy configuration (for example Nginx, Apache, or Traefik) — the body size limit for uploads is too small, so when Nextcloud sends the document to Collabora for preview generation, it gets rejected.

Fix

Increase the maximum allowed request body size for your Collabora subdomain.

Thanks
Darshan

3

I had it set in the server block (nginx) for collabora, but apparently it didn’t apply, so I set this value
client_max_body_size 512;
globally in

/etc/nginx/nginx.conf

Now it works great and the errors are no longer displayed.

I’m curious about one more thing (see picture).
My server is not very powerful
LXC RAM 2GB and 2 CPU cores
Should I increase the performance of LXC (e.g. 4 cores and 4GB RAM)?

Very thanks

server-audit
server-audit626Ă—461 34.7 KB

4

@gusto

You fixed it right.

Your LXC (2 GB RAM, 2 CPU) is fine for 1–2 users.
For smoother performance: upgrade to 4 GB RAM + 4 CPU, or run:

Usage CPUs RAM Notes
1–3 concurrent users 2 2 GB Works, but may swap or lag with large docs or Impress files
4–10 concurrent users 4 4 GB Smooth editing, faster startup
10+ active users 4–8 6–8 GB+ Required for real-time collaboration and previews

I found this nice little thread check it once

Thanks
Darshan

5

In my case, no more than 4 clients will use collabora (or nextcloud).
If the number of clients increases, I will also increase the resources for LXC.
Thank you

1 Like
6

Your welcome @gusto

Regards,
Darshan