A vanished friend, a tragic move, and a desire to communicate

A friend of mine was removed from my friend's list. I didn't delete him, unless I did it unintentionally. He says he didn't remove or block me. And apparently, there's some global setting that won't let you add someone after they've been removed, which is amazingly annoying. He's a really good friend of mine who I never get to see anymore, due to a move, and this is our only way to communicate. Please someone him and me reunite.