Hi, unfortunately Refresh does occasionally cause problems; please look on your Desktop for a file named Old Firefox Data - Refresh Firefox - reset add-ons and settings. Also see the articles below. (You will need to copy the sessionstore.js file to your profile).

• Profiles - Where Firefox stores your bookmarks, passwords and other user data.

• Recovering important data from an old profile.

If your question is resolved by this or another answer, please take a minute to let us know. Thank you!

Do you still have the Old Firefox Data folder on your desktop? You can check for session history files and examine their contents to see which one looks like the latest collection of pages.

Click into Old Firefox Data, then into your semi-randomly-named profile folder. Here you may find the following files:

• sessionstore.jsonlz4 - Firefox 56 session history file created during a normal shutdown
• sessionstore.js - Firefox 55 and earlier session history file created during a normal shutdown
• sessionstore.bak - obsolete file

There is a folder named sessionstore-backups that may contain numerous files. These include:

• recovery.js/jsonlz4: the windows and tabs in your currently live Firefox session (or, if Firefox crashed at the last shutdown and is still closed, your last session)
• recovery.bak/baklz4: a backup copy of recovery.js
• previous.js/jsonlz4: the windows and tabs in your last Firefox session
• upgrade.js/jsonlz4-build_id: the windows and tabs in the Firefox session that was live at the time of your last update

To view the contents of a session history file, you can drag and drop it onto this tool: https://www.jeffersonscher.com/res/scrounger.html (that's on my website, so if it doesn't work, let me know).

You can use that to identify the most promising file, and also to generate a webpage with clickable links from that session, as a backup.