A secure connection error message appears in the Mozilla Firefox browser Sec_error_reused_issuer_and_serial. This error message will appear when you try to access the configuration page of the router. Generally, this problem comes with the old router. The security certificates in the old router generated improperly instead of keeping the same certificate for the device. Until the proper and permanent security will not be added to the router along with appropriate regeneration, Mozilla Firefox will show and detect this error message.
There are some steps to solve the Mozilla Firefox error:
Check Mozilla Firefox SSL Settings – Type about:config in the address bar of the Mozilla Firefox and press enter. A popup will appear showing Accept the Risk and Continue, click on that and also check and tick the box saying ‘Warn me when I attempt to access these preferences’. After that type security.ssl.enable_ocsp_stapling in the search bar. The value mention in that will be True but change it to False by double-clicking. Try to reload the page that shows the error after finishing all the steps. If after reloading, the error displays again then try out some other solutions.
Check Mozilla Firefox Proxy Settings – One may face some security connection error on the Mozilla Firefox if the computer is configured by some proxy for internet access. The error problem can be solved by following some steps. The tools menu is present in the Mozilla Firefox, click on that and further tab on the Options in the menu bar. Now, click on Network Settings and then the Settings button. A popup will appear showing connection settings and in that, you can find the manual proxy configuration option which is enabled. This means your computer is used to configure the manual proxy server. After that, the important thing which you need to check is HTTP, Proxy, SSL proxy, FTP proxy, and SOCKS host fields have entered correctly or not. If these protocol fields are not entered correctly, then change them and press OK. Apart from this, if enable option of manual proxy configuration is not ticked then leave all these steps and directly contact the network connection person who handles all these networks and servers’ issues.
Check SSL Installation or Configuration on Website – One of the reasons for the error in Mozilla Firefox could be incorrectly installed SSL/TLS certificate. The secure connection on Firefox will show failed and display the error code sec_error_reused_issuer_and_serial. So it is highly recommended to properly monitor the SSL certificate installation or configuration on the website by using free tools like SSL Checker.
It was mainly noticed that a secure connection failed error on Mozilla Firefox basically occurs due to old routers or incorrect settings of proxy. If the error message is popping up on your desktop and the above-mentioned steps didn’t help to solve the issue, then don’t get disappointed and try to open other websites or use some other browsers. If then also error message occurs, then directly contact the network operating person so that you will get a perfect and permanent solution.