Accidentally deleted files in SanDiskSecureAccessVault

I accidentally deleted files in my SanDiskSecureAccessVault. So although I can see all the folders in SanDiskSecureAccessV3.01_win, I cannot open them as I get the following message:

SanDisk SecureAccess™ V3.01

The file [IMG_5003.JPG] is invalid and cannot be opened or decrypted. It is either corrupt, been tampered with or belongs to another license.
Do you want to delete it from your vault?

Yes No

Does anyone know if I can sort this or do I have to add the numerous videos and photos again? It has taken many, many hours to add these so would appreciate any advice please?