with fiber optics take care that with multimode fibers you can use 850 or 1300 nm light sources, and with singlemode fibers you can use 1310 or 1550 nm. So check that first if they both work on same wavelength.
Then if you use plug-in cards then take care that fiber optics can connect with only one 10Base or 100Base or 1000Base on both sides. Fiber optics is not 10/100/1000Base like copper connection. So check this also, if cards work with same speed.
Also check that transmit fiber port on one side goes on receive fiber port on the other side , so maybe that you can solve the problem simply by changing connector ports.
If you use one connector fiber optic port than it means that it sends on one wavelength and receives on the other, so you have to use different cards, so that one send and other receives on same wavelength.
Before you check the fiber optic link, check the switch configuration that ports work on same 10/100/1000Base.
If nothing of that helps, then check fiber optic link if it is OK.