[Bug]: App Store screenshot URLs return 404 from usercontent.apps.nextcloud.com

[fds2610]

Bug description

The screenshots of my app are not displayed on the Nextcloud App Store.

The screenshot URLs are correctly defined in info.xml, and the original
image URLs hosted on Codeberg are directly accessible. The App Store
successfully imports the screenshot entries, but the generated
usercontent.apps.nextcloud.com URLs return HTTP 404 (File not found).

As a result, none of the screenshots are displayed on the app detail page.

App information

• App ID: nc_gantt
• App name: Gantt Projects
• App version: 2.1.0
• Release tag: v2.1.0-f901310
• Nextcloud platform: 35
• Repository: https://codeberg.org/fds2610/NC-Gantt
• App Store page: https://apps.nextcloud.com/apps/nc_gantt

Steps to reproduce

1. Open the Gantt Projects app page:
   https://apps.nextcloud.com/apps/nc_gantt

2. Open the screenshot/gallery section.

3. The screenshot area is present, but the images are not displayed.

4. Inspect the page using Firefox Developer Tools.

5. The HTML contains <img> elements whose src attributes point to
   usercontent.apps.nextcloud.com.

6. Open one of these generated usercontent.apps.nextcloud.com URLs
   directly in the browser.

7. The request returns HTTP 404 with the response body:

   File not found

The response is only 14 bytes.

Expected behavior

The screenshots declared in info.xml should be available through the
App Store and displayed in the screenshot gallery on the app detail page.

Actual behavior

The App Store generates/uses usercontent.apps.nextcloud.com URLs for
the screenshots, but those URLs return HTTP 404.

Firefox also reports:

A resource is blocked by OpaqueResponseBlocking

for the screenshot requests.

The direct 404 response appears to be the underlying problem, rather than
a browser-only rendering issue.

Screenshot configuration

The release contains 10 screenshot entries in appinfo/info.xml.

For example:

<screenshot>https://codeberg.org/fds2610/NC-Gantt/raw/tag/v2.1.0-f901310/screenshots/appstore/uc01-project-structure.png</screenshot>

The remaining nine screenshots use the same URL pattern.

All original Codeberg URLs are directly accessible and the individual
PNG files are below 300 KB.

Additional observations

The release itself is correctly available in the App Store. The problem
appears to affect the screenshot resources only.

The App Store page contains the screenshot elements, so the
metadata from info.xml appears to have been processed successfully.

However, the corresponding resources on
usercontent.apps.nextcloud.com are not available and return 404.

This issue was noticed after a recent App Store maintenance/update during
which the App Store was unavailable for several hours.

I have attached a Firefox Developer Tools screenshot showing:

the generated usercontent.apps.nextcloud.com image URL in the HTML;
the failed screenshot requests;
the OpaqueResponseBlocking messages.

Could you please check whether the screenshot/user-content storage or
processing for this app/release is currently broken?

Thank you!

[edward-ly]

Sounds related to or possibly a duplicate of #27 (the difference being the return status of 200 instead of 404). We'll see what we can do in the meantime.