Error: SEC_ERROR_REUSED_ISSUER_AND_SERIAL

Source

Description:
When connecting multiple times to the same system, but - e.g. for testing - the SSL certificates changes all the time, suddenly firefox refuses to connect at all. Other browsers usually work.The error message show is something like: sec_error_reused_issuer_and_serial.

Solution: The quick and dirty way is to remove the certificate storage within the local firefox profile:

    $ rm <profilepath>/{cert8.db,cert_override.txt }

A firefox restart might be required.