Looks like you are using RoboForm Password Manager. You should contact their support.

it hapens if I turn roboform OFF, so that is not the problem

Are the passwords listed in Firefox's Password Manager?

Type about:preferences#security<enter> in the address bar. Look under Logins,

Note: For Firefox 56+ its; about:preferences#privacy Look under Forms & Passwords +++++++++++++++++++++++++++++++ Turn on Remember Logins. To check the passwords you have listed, press Saved Logins.

Press the Exceptions button and see what's inside.

Try to disable accessibility services in Firefox.

• Options/Preferences -> Privacy & Security -> Prevent accessibility services from accessing your browser
• https://support.mozilla.org/en-US/kb/accessibility-services
• http://techdows.com/2017/08/firefox-57-prevent-accessibility-services-accessing-browser.html

I checked and the password IS stored in Firefox.

Changing the accessibility setting did not help, either.

Plesae see the video I made showing the problem of the disappearing password - well your site will not let me upload a 567KB video showing the problem

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

starting in Safe model had no effect on the problem. the password still disappears once the page has finished loading

could the web site in question be set up to erase the password?

radar said

could the web site in question be set up to erase the password?

See this article please, and scroll down to the section 'Websites prohibit password saving' :

https://support.mozilla.org/en-US/kb/usernames-and-passwords-are-not-saved

(Some sites use the 'autocomplete=off' ..... )

While prohibiting password saving is always a problem (a form filling add-on can override this problem) the site would not delete an entered password.

Thanks McCoy. I'll email the site admin to see if they block saving passwords.

FredMcD, are you saying that the function McCoy refers to would NOT erase the password from the sign in box into which Firefox has already entered the password?

thanks

FredMcD said

While prohibiting password saving is always a problem (a form filling add-on can override this problem) the site would not delete an entered password.

You're right : the password will not be deleted. But as the OP says that it only shows up and then disappears : I think that Firefox 'gets ready' to enter the password, but then is blocked by the site.

(autocomplete=off)

I emailed the site admin and he says that what I am experiencing is how they have set up the site. thanks for your help

radar said

I emailed the site admin and he says that what I am experiencing is how they have set up the site. thanks for your help

Thank you for letting us know  !

Did they mention how  ? Do they use 'autocomplete=off'  ?