If your capture tab shows “missing/invalid key” or “session expired”, it means the capture session can’t be found anymore.

TL;DR

• Re-capture and open Lliben Capture again.
• Don’t refresh the capture tab mid-flow.

Common causes

• The tab was open for a long time before you used it
• The capture tab was closed and reopened
• The page was refreshed mid-flow
• The browser cleared session state

Fastest fix

Simply take the screenshot again and reopen Lliben Capture from the new capture.

Best practices to avoid it

• Don’t refresh the capture tab while editing/exporting
• Export your result (PNG/JPG/PDF) soon after you capture

Related:

• Chrome screenshot extension hub
• Support & FAQ