This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Este fío arquivouse. Faga unha nova pregunta se precisa axuda.

firewall SSL certificate , SEC_ERROR_REUSED_ISSUER_AND_SERIAL

  • 2 respostas
  • 1 has this problem
  • 2 views
  • Last reply by cor-el

SohX
SohX
more options

Dears, i have renewed our corporate security certificate on microsoft certificate authority server, and imported it into our firewall like the old certificate. however, we imported the certificate into firefox , but when anyone try to connect to any https website , it returns this error SEC_ERROR_REUSED_ISSUER_AND_SERIAL or Your connection is not secure .

even tho the same certificate is working properly on chrome and IE, but we need firefox.

troubleshooting steps:

1- i have changed security.enterprise_roots.enabled; from false to true 2- security.ssl3.dhe_rsa_aes_256_sha; changed from true to false 3- security.ssl3.dhe_rsa_aes_128_sha; changed from true to false

but it doesnt fix our issue. note: firefox ver 58.0.2 and 58.0.1.

Dears, i have renewed our corporate security certificate on microsoft certificate authority server, and imported it into our firewall like the old certificate. however, we imported the certificate into firefox , but when anyone try to connect to any https website , it returns this error SEC_ERROR_REUSED_ISSUER_AND_SERIAL or Your connection is not secure . even tho the same certificate is working properly on chrome and IE, but we need firefox. troubleshooting steps: 1- i have changed security.enterprise_roots.enabled; from false to true 2- security.ssl3.dhe_rsa_aes_256_sha; changed from true to false 3- security.ssl3.dhe_rsa_aes_128_sha; changed from true to false but it doesnt fix our issue. note: firefox ver 58.0.2 and 58.0.1.

All Replies (2)

FredMcD
FredMcD
more options

There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate.

https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites

https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message

https://support.mozilla.org/en-US/kb/connection-untrusted-error-message

http://kb.mozillazine.org/Error_loading_websites

https://www.bing.com/search?q=web+site+access+denied

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

Try to rename/remove cert9.db and when present cert8.db in the Firefox profile folder with Firefox closed.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.