I downloaded Enpass for windows about 30 minutes ago have exactly the same problem master password correct but rejected, tried using a text editor as suggested same issue, copied file with password to my Linux machine which has an older version, worked fine there, on re-opening Enpass I noticed the activation prompt and ran the activation process after which it accepted the password and synced up with no issues.
I don't recall seeing the activation prompt on the initial open which was done from the post install link
Hope this helps
