This error message is an indication that the vault index file has somehow become damaged or corrupted. If you have version 5.4.16 (or later) of the software installed, you can likely repair the file with the following steps:
- Copy the Vault file on the flash drive or hard drive and paste it to your desktop as a backup in case it is needed;
- With either Windows Explorer or Finder (for Mac) navigate to the directory folder that contains the DataVault application;
- Open the Vault folder and locate the file “index.dat”;
- Change the name of the file to “index2.dat”;
- Close Windows Explorer (or Finder);
- Run the program and log in with your password;
- If you are able to log in, you will see the vault (on the USB or computer) with an X;
- Right click on the vault icon. click > Properties > Repair Vault.
You will now be able to access the files in the Vault.