So I took over this really old FileMaker 7 (possibly from FileMaker 5) database. I'm currently on FileMaker 11 Advanced. Nobody in the office knew the password but luckily it was saved as an auto login. I could get into the database but I could add accounts or change existing accounts. I racked my brain and searched the net. I always try to go the cheap way so buying something was not my plan. I looked at countless solutions that seemed so tedious.
This is what I did... so easy... I added a new account with full permissions. Then when I went to save the settings and of course it asked for my username and password. I simply entered the username and password I just created and whammo!
Anyways, I thought I'd pass this on in case it was a bug or something.