Are you using "Clear history when Firefox closes" to clear the history and the cookies ? *Options/Preferences -> Privacy & Security<br>Firefox will: "Use custom settings for history":<br>[X] "Clear history when Firefox closes" -> Settings *https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox You can check that you aren't clearing cookies you want to keep. *using "Delete cookies and site data when Firefox is closed" keeps cookies with an allow exception *using "Clear history when Firefox closes" to clear cookies clears all cookies including cookies with an allow exception you may want to keep *clearing "Site Preferences" clears exceptions for cookies, images, pop-up windows, and software installation and exceptions for passwords and other website specific data *Options/Preferences -> Privacy & Security<br>Cookies and Site Data: "Manage Exceptions/Permissions" Note that you can't use "Restore Previous Session" if you use "Clear history when Firefox closes" to clear the "Browsing History".