Looks like the problem is not fixed completely as error 502 is still occurring for me or the rolls are working but extremely sloooow (both on FreeBitcoin and FreeDogecoin).
On the other hand, Id like to state that all my experience (not very long though, about 15 months or so) as well as everything Ive heard or read absolutely approve this projects reputation. Actually, if you believe in crypto you may stay assured on FreeBitco.in (and vice versa lol).
Keep calm and carry on :].