I successfully setup the reverse proxy for my lync server with forefront TMG. When I test the published IIS pages externally on a laptop that is joined to the domain it works with no issues as per the instuctions i followed from technet to create reverse proxy.
If I try connecting from a non domain pc i get the cert error. I have tried exporting the CA chain and public edge cert with still no luck.
Is there a security setting that is blocking this somewhere?