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How to access my website at my dev machine without getting: Secure Connection Failed

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I'm working on a website and access it via https using a selfsigned certificate When I try to access it i got the following error:

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An error occurred during a connection to api.couriercloud.tk. You have received an invalid certificate. Please contact the server administrator or email correspondent and give them the following information: Your certificate contains the same serial number as another certificate issued by the certificate authority. Please get a new certificate containing a unique serial number. (Error code: sec_error_reused_issuer_and_serial)

   The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
   Please contact the website owners to inform them of this problem. Alternatively, use the command found in the help menu to report this broken site.
I'm working on a website and access it via https using a selfsigned certificate When I try to access it i got the following error: =================================================================== An error occurred during a connection to api.couriercloud.tk. You have received an invalid certificate. Please contact the server administrator or email correspondent and give them the following information: Your certificate contains the same serial number as another certificate issued by the certificate authority. Please get a new certificate containing a unique serial number. (Error code: sec_error_reused_issuer_and_serial) The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem. Alternatively, use the command found in the help menu to report this broken site.

All Replies (3)

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Deleting an old saved certificate could be your best workaround. Try the steps in this article: Certificate contains the same serial number as another certificate. Any luck?

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Didn't work !!! :(

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Did you manage to locate the other certificate(s) with the same serial number in the Certificate Manager?

If not the try to rename the cert8.db file (cert8.db.sav) in the Firefox profile folder to see if that works.


Rename the cert8.db file in the Firefox profile folder to cert8.db.old or delete the cert8.db file to remove intermediate certificates that Firefox has stored.

If that helped to solve the problem then you can remove the renamed cert8.db.old file.
Otherwise you can rename (or copy) the cert8.db.old file to cert8.db to restore the previous intermediate certificates.
Firefox will automatically store intermediate certificates when you visit websites that send such a certificate.

If that didn't help then remove or rename secmod.db (secmod.db.old) as well.