Firefox “invalid certificate” error for a trusted website (sec_error_reused_issuer_and_serial)

I ran across the same issue. Found the answer.

1. Go to Control Panel > Network and Internet > Manage Wireless Networks.

2. Open the wireless network. Or, click the "Add" button to create a new network, then open it.

3. The Wireless Network Properties window appears. Click the Security tab.

4. Under "Choose a network authentication method", select "Microsoft: Smart Card or other certificate". I assume this is already selected.

5. Click the "Settings" button.

6. The "Smart Card or other Certificate Properties" window appears.

7. Here is the answer. Under the "Trusted Root Certification Authorities" list, you have to manually select the Root CA of your company. By default, these are all blank. That is why the warning message appears the first time if you do not select your company's Root CA. If you connect despite the warning, then your company's Root CA is now selected, and you no longer get the warning on subsequent connections. So, to avoid the warning, just select this box when you set up the network, before you connect for the first time.

8. If you do not see your company's Root CA here, that is likely due to the fact that by default, double clicking your certificate to install it probably puts it under the "Intermediate Certification Authorities" tab. You need to select the "Trusted Root Certification Authorities" tab instead. You can see where certificates go under: Internet Explorer > Internet Options > Content > Certificates

Issue #1: sec_error_ocsp_server_error can occur for other reasons than OCSP server internal error.

From Bugzilla bug 495380:

SEC_ERROR_OCSP_SERVER_ERROR is used 5 times in ocsp.c for everything from an internal OCSP server error to failing create the request session and any number of different problems writing the request to the remote server.`

Issue #2: I believe that Firefox is caching this error but should not do so, so I created Bugzilla bug report 1014979.

Workarounds (from a post that I wrote at another forum):

Method #1: Restart Firefox.

Method #2: Go to Options->Advanced->Certificates-> Validation. Set checkbox "When an OCSP server connection fails, treat the certificate as invalid" to the opposite of what it is now, and then press OK button twice. That is sufficient to clear the OCSP cache. However, since you probably want the original setting that you just changed, go to Options->Advanced->Certificates-> Validation and set checkbox "When an OCSP server connection fails, treat the certificate as invalid" back to the value that was there before you read this post, then press OK button twice.