caligraphy

Problem with Ligatures on Fontlab

Forums: 

Good morning, everyone. I’m new at this forum, although I’ve been reading it since a very long time. My name is Mauricio Villamayor, I'm designing a calligraphic typeface for my thesis and I have a problem in doing it. I hope if you can help me with this situation.

Basically, the problem is with the ligatures. The typography has a lot of them, since the calligraphic characters are more complicated to bond harmonically. The ligatures work in all the combinations, except in the accented (acute accent) letters.
For example, a specific ligature exists for the combination “yo” (which works), but when I create the combination “yó”, it doesn’t work, indicating an error when I compile the ligaduras.

This is the specific error that shows: