Tabiary

Tab Session Manager lost my sessions: how to recover them

"Lost sessions" can mean two different things: the session list is empty, or the sessions are listed but will not open. They need different fixes.

Before anything else

  1. Do not uninstall or "repair" the extension. Removing an extension deletes its stored data, and Chrome's repair prompt reinstalls it clean. Whatever is still on disk goes with it.
  2. Quit Chrome completely and make a copy of your whole profile folder (table below) before trying anything else. Every later step is safer with that copy.
  3. Do not run cleaner tools (CCleaner, "free up space" utilities) until you are done. They are a common cause of the loss in the first place.

If the sessions are listed but will not open

Your data is still there. Get it out before trying to fix the extension.

  1. Open the extension's settings and use its export option to save your sessions to a file.
  2. Keep that file somewhere safe before you change anything.
  3. Only then try the usual fixes: restart the browser, update the extension, or reinstall it and import the file.

If the session list is empty

  1. Look for backup files. If you had turned on a backup option in its settings, search your Downloads folder for files or folders with "TabSessionManager" in the name.
  2. Check cloud sync. If you had connected a cloud account in its settings, sign in again and let it sync before saving anything new.
  3. Check other browsers and profiles where you had it installed. Each keeps its own list.
  4. Restore the extension's data from a system backup. Quit the browser, then restore the extension data folders in your profile (IndexedDB and Local Extension Settings, the entries containing the extension's ID) from a date before the loss, using Windows "Previous versions" or File History, or macOS Time Machine. In Chrome the extension ID is iaiomicjabeggjcfkbimgmglanimpnae; you can confirm it on chrome://extensions with Developer mode on.
SystemChrome profile folder
Windows%LOCALAPPDATA%\Google\Chrome\User Data\Default
macOS~/Library/Application Support/Google/Chrome/Default
Linux~/.config/google-chrome/Default

If you use several Chrome profiles the folder is called Profile 1, Profile 2 and so on instead of Default. Open chrome://version and read the "Profile Path" line to be sure.

If the browser crashed and auto-save has nothing recent

Then the tabs were open in the browser, not saved in the extension, and the browser's own recovery is your best route: recover tabs after a Chrome update or crash.