If the file is credible - check that in another model program if possible.
Then you may have to move the models position in Fragmotion I guess. Presumably the model and central axis vetrex is in the correct place in Fragmotion. i.e. its has not changed.
I have had such problems. If the model is credible then it may just be out of Camera view in FPSC.
You could also try saving out from another modelling programme (Milkshape?)
You may be best advised to wait for more responses as others may be able to help further or better than I.
Whatever I suggest you always keep a backup of files - more than one copy you can go back to before making major changes or come across any issues. Always keep a backup copy of things.
There are those that said this day would never come. What have they to say now?