Does the master password work when logging into other websites that are also stored in the browser. You can view the login/pass in Options - Security - Saved Passwords (the Show Passwords bottom right of the popup).

I would suggest typing the master password (no spaces before or after) into a text editor (notepad) and then copy/paste in, to ensure you are typing the correct password.

Also checking caps lock is not on too (though I can see you're not shouting :))

Also make sure that CAPS lock isn't on.

Is the password for the sync the same as it is for the Mozilla support? I have (apparently, don't remember doing it) set up the sync account on my desktop. It is set up, allowed me to change my preferences as to what I want to sync. I then went to set up my laptop, clicked on "already have an account" and typed in the password I use for Mozilla support and it says it is the incorrect password. I don't have a master password set up, but looked under "saved passwords" and there is nothing there (I don't save passwords as a preference, as I have a program that does that for me) What do I do? The "manage account" only gives me an option to change the password, if I know the old one. No option to request a new one. I just tried changing it on the desktop, that too says I have the wrong password. I have no idea how to figure out what the right password is

csutak40,

The question posted in the initial posting was a bit vague. In Firefox the "Master Password" usually refers to this - https://support.mozilla.org/en-US/kb/use-master-password-protect-stored-logins - and it shouldn't prevent a user from loading any web page. When a user who has the Master Password feature set up in Firefox loads a web page that has a Password saved in the Firefox Password Manager, Firefox will ask for the user's Master Password.

As far as your situation, No - the Password for this forum - Mozilla Support - won't work for Sync - it isn't used any where else, within Firefox like for Sync and "Firefox Accounts" or any other mozilla.org sub-domain. No problem with using the same user name and password for then all, but when you go to login to any of them the username and password won't be "auto filled" until you save them for each sub-domain.

You need to use the password for "Firefox Accounts" that you used when you first setup Sync. And as far as not saving any passwords in Firefox, I believe that the Sync service won't work if you don't at least use the built-in Password Manager for saving your Sync Mozilla Services Password and the Mozilla Services Passphrase [which is used for encryption of your data]. I doubt if whatever you are using for saving passwords externally (outside of Firefox) is going to be able to deliver both the Password and the Passphrase that Sync needs to work properly.

Thank you it is sorted (well, the pasword part is) It let me re-set the password on the laptop - it didn't ask me for the old one there. So, now I have a new password. The sync worked - in a fashion. I think I need to write a separate post about that

I do not know nor do I remember setting my Master Password . How can I find what it is ?

J.L.Beitler,

You can't "find it". The best you can do is to reset it - which will allow you to "start from scratch". All your Passwords will be deleted. https://support.mozilla.org/en-US/kb/reset-your-master-password-if-you-forgot-it