These are tabs that have been suspended by
The Marvellous Suspender extension.
If there's just a few of them, you can update the URL of each link by right-clicking it and then clicking "Edit..."
If there's a lot, do an Export to get a json file (IMPORTANT: use Backup instead if it's available, which it will be for Session Buddy v4.0.5 and later).
Edit the backup file to remove the URL prepend (global search and replace in something like
Notepad++). Then re-install Session Buddy and
Restore the file.
Hans