Paste one or more download links
The Copy tab needs at least one public download link before it will start. Product text: “Paste one or more download links (one per line).”
Why this happens
This is client validation in the uploader before POST /api/upload/copy-from-public. The textarea was empty or only whitespace after trimming lines. It is not a plan block or a size error.
Diagnose and fix
1. Paste one public file URL per line, then run Copy again.
2. If the Copy tab is missing: Mods → Copy from public must be on.
3. If Copy is visible but blocked for the plan, you will see a different message (Copy files not allowed for your plan).
4. Empty Remote URL field is a different prompt (Enter one or more URLs).