Password is not valid

Guys

I have a 4TB WD My book with 1TB used and 3 dayas ago I have set the password. I am sure about which password I have set but after I turn off the equipment and turn on again it says tha password is not valid.
What should I do? I can not lose my data.

Hi freitasmad,

You can refer to the link given below for the resolution for the invalid password issue on the drive.