Upload fails after increasing Nginx file size limit (previously 413 error)

[eliotschmitt]

Attempted Debugging

• I have read the debugging page

Searched GitHub Issues

• I have searched GitHub for the issue.

Describe the Scenario

I recently updated my Nginx configuration to increase the allowed file upload size, as I was previously encountering a 413 Request Entity Too Large error when uploading a book cover image.

After increasing the limit (using client_max_body_size), the 413 error is resolved. However, I am now encountering a different error when attempting to upload the same image.

Steps to reproduce:

Go to the book creation/edit page
Upload an image as the "cover" (couverture)
Submit the form

Expected behavior:
The image should upload successfully and be saved as the book cover.

Actual behavior:
An error 500 occurs after submission.

Exact BookStack Version

v25.12.3

Log Content

Hosting Environment

VMware Photon OS

docker-composse.yml
services:
bookstack:
image: lscr.io/linuxserver/bookstack:latest

bookstack-db:
image: mariadb:11

[ssddanbrown]

Hi @eliotschmitt,

An error 500 occurs after submission.

If it's a relatively blank error page (no BookStack UI/design) then the error will likely be logged to the webserver which is producing that error, so either the nginx web-server in-container, or potentially an proxies you have sat in front (if any).

In my video here, I explore the various log files for the linuxserver image, including those for the web-server:
https://youtu.be/6A8hLuQTkKQ?t=448