How long is the fiber, and what kind is it (singlemode or multimode, if multimode, what is the core diameter, 50 or 62.5 micron)?  Also, remember that the transmit side on one transceiver must be connected to the receive side of the other, and vice-versa.  If in doubt, try swapping the two fibers at the switch or patch panel, but only in one place.  The optical tranceiver diagnostics will not work unless there is a link up, it won't show up at all.  There is no config you need to do to enable the fiber ports.