When using Microsoft Access to open a corrupted Access database file, it will display the following security warning message :

This file may not be safe if it contains code that was intended to harm your computer.
Do you want to open this file or cancel the operation?

A sample screenshot looks like this:

Precise Explanation:

There are many reasons that will cause this error, including the corruption of the Access database, especially when the corruption is caused by virus infection.

If you can confirm the reason is file corruption, then the only solution to this problem is using our product DataNumen Access Repair to repair the MDB file and solve this error.

Sample File:

Sample corrupt MDB file that will cause the error. mydb_11.mdb

The file repaired with DataNumen Access Repair: mydb_11_fixed.mdb