Infinispans banner on main page (http://localhost:11222) redirects to https://www.infinispan.org which doesn't have valid certificates. Certificates on that page are valid only for github.com. Quoting Firefox:

Firefox does not trust this site because it uses a certificate that is not valid for www.infinispan.org. The certificate is only valid for the following names: www.github.com, *.github.io, *.githubusercontent.com, *.github.com, github.com, github.io, githubusercontent.com

Either link should be fixed to point to https://infinispan.org with valid certificates or fix the page's certificates.