App Store screenshots return "File not found" through usercontent.apps.nextcloud.com #27

Description

Screenshots for my newly published app, Markdown Wiki (markdown_wiki), are not displayed on the Nextcloud App Store.

The App Store detects the screenshots and displays the screenshot carousel and navigation arrows, but the images themselves are blank.

The screenshot URLs are public HTTPS URLs hosted on raw.githubusercontent.com and work correctly when accessed directly.

Example

Screenshot URL:

https://raw.githubusercontent.com/JoaoMSacramento/markdown-wiki/main/screenshots/markdown-wiki-main.png

Direct request works correctly:

HTTP 200
Content-Type: image/png
Content-Length: 259713

However, when the same URL is requested through usercontent.apps.nextcloud.com, the response is:

HTTP 200
Content-Type: application/octet-stream
Content-Length: 14

File not found

Tests performed

I tested:

• The screenshot from the main branch
• The screenshot from the v0.1.1 tag
• The same image copied to appinfo/screenshot.png

All of them are accessible directly from raw.githubusercontent.com, but all return File not found through usercontent.apps.nextcloud.com.

As a control test, I tested the screenshot used by the Memories app:

https://raw.githubusercontent.com/pulsejet/memories/master/appinfo/screenshot.jpg

The Memories screenshot works correctly through the same usercontent.apps.nextcloud.com service.

This suggests that usercontent.apps.nextcloud.com is reachable and can retrieve images from raw.githubusercontent.com, but for some reason it cannot retrieve the Markdown Wiki screenshots.

App information

• App ID: markdown_wiki
• Version: 0.1.1
• Repository: https://github.com/JoaoMSacramento/markdown-wiki
• App Store page: https://apps.nextcloud.com/apps/markdown_wiki
• Supported Nextcloud versions: 31–34