That may indeed be your problem, or part of it.
I was actually able to look at your sketches, *I still had an install of 2014 for evaluation). I think you might want to look into simplifying your sketches a bit, there is a lot going on with all of the work planes and sketches all over the place. A lot of what you have here might be accomplished with using 3D sketches. I did notice that sketch1 was not fully constrained, and several others are also not. Without the complete assembly it's still difficult to tell what your specific problem is, but getting these sketches under control would be a start.
I don't recommend changing your entire structure now,... you're so far into it. But look into 3D sketches for future work, there is a lot less chance for cross part reference failures, and it simplifies your assembly greatly.
In my experiences with FG, I can say that sometimes you have to delete a member and replace it to get it to update. I can't remember if I asked this up above, but have you tried "Rebuild All"? Try it at different levels of the assembly and see what that does for you.
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