I could not make my cables work at first. Was struggling until I remembered that you must have the fibre equivalent of a crossover connection to make things work (Sending fibre must be connected to the receiving fibre on the other end)
So finally realizing that I noticed that you can remove the piece of plastic holding the two individual SC connectors and then switch them around. I did that on one end of the connection and everthing worked perfectly at that point.
Also useful to know that the two halves can be split apart if your device or jack do not have the two SC connectors at the exact distance of the duplex configuration would give you. You can split them out and plug each in individually.
To remove that piece (The part that has the label A and B on either side) You can either push them apart in the middle where there is a hole for a mini sized flat screwdriver to fit or you can just pry them apart with your fingernails.
In my case, I had one set of cables I wanted to reverse and another set of cables where I needed to plug them in individually because the junction box on the wall did not use the standard duplex spacing. For some odd reason we have one junction box which uses the perfect duplex spacing and another box which does not.