You need the correct account name and password. The account name or password sent to you is incorrect in some way. Passwords are case sensitive so it may be that you need to use the correct combination of upper and lower case letters in the password.
You'll need to check with the person who sent you this file to figure it out.
I have correct account name and password, as the other person is able to open the file with the same account name and password combination. Is there any way, to open the file using guest account?
P.S. I am using File Maker Pro 11 on mac OS X (Lion).
Sorry, but if you entered the correct account name and password the file would open. The difference may be very subtle, but there is some difference between what you are entering and what the other person enters to open the file--which is one reason why I suggested checking to see what letters should be capitalized as this is the most frequent "oops" that can keep a person out--especially if they accidentally have the caps lock down.
You won't be able to open the file as a guest unless the file has been set up to enable the guest account. That may get you into the file to look at it, but you'll not be able to do much more than look in most cases.
I have one more small question, (this may sound absurd, but your answer will be a great help to me.. ) The username, "Admin" on one person's machine and on my machine are different? If the username for the file is "Admin" then, what should I enter while logging in?
This is the account name, not the user name. FileMaker enters the user name as the account name for you in the password log in dialog when you attempt to access the file. The user name is a value specified in Preferences so it can be different on each machine--resulting in a different "default" account name in the password dialog for different machines.
Each account defined in manage | Security has a unique name and only one password assigned to it. The account names are not case sensitive.
Thus, if the person that sent you the file is using:
Account name: Administrator
and you use:
Account name: Admin
You will not get access to the file until you change Admin to Administrator and then use Abc as the password.
Thanks a lot... I am now able to open the file.. :)