Hi Brego, the way that sites recognize your browser is because when requesting a page on the site, Firefox returns a cookie the site had previously set after doing the earlier verification. If for any reason that cookie

• is deleted
• is corrupted
• expires
• becomes invalid

then the site will force you to do the verification again.

Since the problem affects multiple sites all at once, my guess would be that cookies were "cleaned up" somehow, and given the long time period, it must not be a regularly scheduled event (unless the schedule is to do it monthly). This could be difficult to track down...

Some users have said there are add-ons that can preserve cookies for specific sites and restore them when they go missing, but I haven't tried that myself.

Make sure you are not using 3rd party programs to clean Firefox. The browser can be set up to do its own cleaning.

Also, some security programs have clean-up tasks included in them.

I recently installed AVG, so that may be related for the current episode. Earlier ones, I have no clue. Firefox has its own built in process for cookies cleanup/restore/preserve?

Hi Brego, I'm going to paste something from another thread:

Usually after the extra authentication (security questions, code sent to your phone, etc.), the site will set a cookie showing that you (your current browser) passed the test. As long as Firefox keeps sending the site that cookies, you do not have to pass their test again.

How can this go wrong?

(1) If you are visiting the site in a private window

Cookies are not written to disk in private windows, so whether they are session cookies or have an expiration date after we're all gone, they will evaporate when the last private window is closed in your session.

The two ways a site could open in a private window are:

(A) Creating a private window in a regular session (for example, Command+Shift+p or right-click > Open Link in New Private Window)

(B) Setting Firefox to use automatic private browsing on the Preferences page --

• Windows: "3-bar" menu button (or Tools menu) > Options
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

In the left column, click Privacy & Security, then scroll down to the History section. Either of these will invoke automatic private browsing:

• Firefox will: Never remember history
• Firefox will: Use custom settings for history + "Always use private browsing mode"

(2) If Firefox is set to store ONLY session cookies, and you have not made an exception for the site.

You can check for this on the Preferences page, Privacy & Security panel, Cookies section. Make sure you do NOT have a checkmark for "Delete cookies and site data when Firefox is closed". If you do, you need to create "Allow" exceptions for sites where you want Firefox to accept persistent cookies.

(3) If Firefox is set to Clear History When it Closes and that includes Cookies

Most people do not have this setting, but you can double-check here: On the Preferences page, Privacy & Security panel, History section: make sure you do NOT have a checkmark for "Clear history when Firefox closes". If you want to use that feature with some types of data, use the Settings button to the right of it to confirm that Cookies are not being cleared. (Also, do not clear Site Preferences if you have made exceptions.)

(4) If you use an add-on that modifies how cookies work

There are extensions to manage cookie lifetimes and removal, including some that expire cookies for inactive tabs. There also are extensions that isolate pages in a container, which creates a separate cookie jar for the pages in that container which are invisible to pages outside that container.

(5) If you logged out of the site

(Not applicable to device identification cookies)

The cookie identifies you to the site, but if your session ended, the site isn't going to start a new one automatically. So if you logged out on the site -- highly recommended for sites that have sensitive data or accounts you can't afford to have taken over -- then the site might pre-fill your user name on the login page, but you will need to sign in again.

(6) If external utility or privacy software cleans browser cookies

If you use CCleaner, Advanced SystemCare or other third party programs that touch browser data, set them not to touch Firefox data.

(7) If your IP address is unstable

Some sites link your identification to your IP address and require a new login if that changes. To minimize the potential for changes, you can check your Firefox connection settings on the Preferences page.

In the search box at the top of the page, type proxy and Firefox should filter to the "Settings" button, which you can click.

The default of "Use system proxy settings" piggybacks on your system settings (for example, Windows/IE "LAN" setting). "Auto-detect" can lead to a flaky connection. You may want to try "No proxy".

Does any of that help?

Does this coincide with a Firefox update ? Some website invalidate 'remember me' cookies if they detect a change in the user agent that happens if a major update occurs.