I've played with your model and got it to mesh: FullyFurnishedBoeing03rayInc.mod.cfx
Copied the original geometry out of the stitched part;
Used the "Repair" tools on the primitive objects to change their internal representations and tweak the tolerances
Stitched the parts together again with a tolerance of "0.1"
I'm not sure why it stopped working between versions. It might just be that there was a library upgrade that affected the way a tolerance influenced the model's validity when you meshed. For now, you should be able to continue working anyway.
PS: I used CADFEKO 14.0.432-293039 (x64) from 2016-12-06