Firefox detected a potential security threat and did not continue to type_safe.foonathan.net.
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Firefox does not trust this site because it uses a certificate that is not valid for type_safe.foonathan.net. The certificate is only valid for the following names: .github.io, github.io, .github.com, github.com, www.github.com, *.githubusercontent.com, githubusercontent.com
Error code: SSL_ERROR_BAD_CERT_DOMAIN