You can see that your system only enters 3 trades, so its results are random. The WFO version will most likely not enter a single trade, so the system does not produce a result.

For WFO you should aim for about 50..100 trades per cycle when you optimize 2 parameters.

For avoiding the warning about missing 2014 data, either download it from FXCM or put "EndDate = 2013;" in your script.