Have .DAT files, I have password, but NOTHING IN VAULT

I am in the same boat BaySailor… I just for the life of me can’t fathom how I can have the .dat files, know the password to decrypt them but can’t get the vault to recognize them… 

Surely the people that designed the program can’t be so dumb that they have no solution for this…however time consuming… I have unrecoverable data that I can’t access… Like life important stuff…