Importing Problem

Hello, I am looking for help with a problem I have in blender. I am trying to make a animated character for a video game, but when I export it and load it into my game the model is lying perpendicular to the skeleton. I have done some trouble shooting and I have narrowed it down to being a problem with importing, I am convinced of this because when I make a model from scratch and export it to my game the problem doesn’t happen. I have tried on multiple versions of blender, but it is always the same. I also know that it is not a problem with the model because this happens with every model I try. Can some one please help me with this issue, it has been holding me back for days now!