While using a MacBook Pro with Firefox ESR 31.6.0, I needed to have it "forget" a certificate for a website that I had it temporarily accept, because of an issue with the site's certificate. The process for doing so is as follows:
- In Firefox, click on the icon of three short horizontal bars at the upper, right-hand corner of the Firefox window, which will give you a menu where you should select Preferences.
Select Advanced and click on the Certificates tab under
- Click on View Certificates.
Click on the Servers tab.
- Locate the server for which you wish to delete the certificate. It will have a lifetime value of "Permanent", if you permanently accepted it or a value of "Temporary", if you only temporarily accepted it. Click on it to highlight it, then click on the Delete button.
- You will then see a message asking "Are you sure you want to delete these server exceptions", which will show the server(s) you have selected and also note "If you delete a server exception, you restore the usual security checks for that server and require it uses a valid certficate." Click on OK. If you want to view the certificate before deleting it, you can click on the View button.
- Click on OK to close the Certificate Manager window. You can then close the Advanced window.