Solution
• To solve this, simply restore the file Folders.dbx.
• Search for Folders.dbx using the search tool(Start/Find/Files or Folders).
• Rename the file to make a backup, for example Folders.bak.
• Launch Outlook Express. Folders.dbx file is automatically recreated and the application opens correctly.
If you are still experiencing the issue after applying this fix you can try to stop the error here:https://onlinefilerepair.com/en/outlookexpress-repair-online.html