[Bug]: 404-Errors for Fast-Add Items / Thumbnails for Fast Add Downloads

I've read the documentation

• I'm running the latest version of Tube Archivist and have read the release notes.
• I'm beta testing and am running the latest unstable build.
• I have read the how to open an issue guide, particularly the bug report section. I've double checked that I don't open a yt-dlp issue here.

Operating System

Proxmox LXC

Your Bug Report

Improvement Proposal: Generate Placeholder Thumbnails for Fast Add Downloads

First of all, apologies if this has already been reported or if there is already an existing issue covering this behavior. I searched but couldn't find a report that matched this specific problem.

Problem

When videos are added using the Fast Add feature, no thumbnails are generated initially.

If the Download Queue is opened, the frontend requests thumbnail files that do not exist yet. This results in multiple 404 Not Found responses.

While this is usually harmless, it can cause issues in environments where reverse proxies or security middleware monitor HTTP errors. For example, I use BunkerWeb with the Bad Behavior module. Every 404 response increases its internal counter, and after enough missing thumbnails, my own IP address is temporarily banned because the requests are interpreted as suspicious behavior.

Suggested Improvement

Instead of referencing thumbnail files that do not exist, one of the following approaches could be used:

• Generate a placeholder thumbnail when a video is added via Fast Add.
• Prevent the frontend from requesting thumbnail URLs that are known not to exist yet.

Benefits

• Eliminates unnecessary 404 responses.
• Improves compatibility with reverse proxies, WAFs, and security tools that monitor error responses.
• Reduces noise in server logs.
• Provides a cleaner user experience while downloads are pending.

Additional Context

This issue may not be noticeable in a default installation, but it becomes problematic in setups using security solutions such as BunkerWeb with the Bad Behavior module, where repeated 404 responses can trigger automated IP bans.

Thank you for all the work on Tube Archivist!

Relevant log output

Didn't see 404 in Docker-Logs.

Anything else?