If you like me suffering from openning too many tabs in Firefox browser to the
point where limitation become an ability of Firefox to start with all of these
tabs (it is simply crashing after launch) you can edit or recover your opened
tabs from sessionstore.jsonlz4 file or or similar backup files from
sessionstore-backups directory.
Placing back edited sessionstore.jsonlz4 you can let your Firefox to start
and save some tabs to bookmarks or close them in the browser.