You are trying to open a newer database with an older version of Access (e.g., opening a Microsoft 365 file in Access 2013).
The most straightforward way to open is to have Microsoft Access installed. Simply double-click the file in Windows Explorer to launch the application. Don't have Access? You still have options:
One of the most common headaches for Access users is the "Unrecognized Database Format" error. This often happens if:
Free tools like the MDB ACCDB Viewer allow you to browse tables and run searches without a full Office license. 2. Troubleshooting "Unrecognized Database Format"