I found a mis-alignment problem after importing two 3D models. I checked the origin points of the two models and they are in different locations in the modeling software.
If the models have different origin points in the software, you can translate one on import so that they are aligned. Import the 2 files separately using File>Import>3D. For the file to be translated, select the Next> button until you see this screen. Enter the difference between the two origins and select Relative. Then Import. The files should be aligned.