It seems that your prefs.js file is corrupt and has been renamed in
"prefs-1.js" or "invalidprefs.js" on a TB startup while TB has created a
new "pristine" prefs.js file which doesn't contain your account
settings. That's why TB actually cannot display your accounts and
folders. This can happen when the system or Thunderbird crash.
If you have a backup copy of your profiles, open it and copy the
prefs.js file from the "12345.user0" profile folder.
Open your actual "12345.user0" profile folder, shut down Thunderbird,
remove the prefs-1.js or invalidprefs.js and the prefs.js files and
replace them with the prefs.js of your backup.
Restart Thunderbird, all your accounts, folders and messages should be
displayed now.
If you don't have a profile backup to copy the prefs.js file from,
you'll have to recreate all your accounts.
If you have been using IMAP accounts, all your folders and messages will
be synchronized. If you have POP accounts you'll have to link the newly
created POP accounts with their respective previous message store local
directories (the "pop.xxx.xx" folders in the "Mail" folder) via Tools >
Account Settings > %Account_name% > Server Settings > Message Storage >
"Browse".