What this error means
When you start a download from a website, the browser hands XDM the address together with the cookies and headers that prove you’re allowed to download. Many sites keep that permission only for a while, or only while you stay signed in. When XDM later tries to continue, the server no longer recognizes the session and refuses the request.
Fix: refresh the link
- Make sure you're still signed in to the website in your browser.
- In XDM, right-click the download → Refresh link.
- Click Open containing web page and start the same download again in the browser (for videos, play the video and choose the same quality).
- Accept the new link when XDM asks. The download continues from where it stopped.
See the full walkthrough in Resume a download with Refresh link.
Avoid it next time
- Don’t sign out of the site while its downloads are paused.
- Start large downloads from sites with short sessions right away instead of using Download later.
- If the site sends you to a different mirror each time, refresh promptly after an interruption.