Whn I load a backround layer it does not show up. I have loaded DXF and SHP files and cannot see them. Can you help me with this?
Try doing a Zoom Extents to see what happens. If the DXF or SHP files are not on the X:Y coordinates as the model you may see something like this. This link has some information on this.
If that is the case, I would recommend using the original platform for the file (AutoCAD, MicroStation, ArcMap) to move the background layer to the correct location.
Another thing you can try is to open a new model and load the background. You will likely need to do a Zoom Extents to see it. You can note the coordinates for the background layer compared to the model coordinates.
This Wiki article suggests when attaching background files, try turning off the option to Use Compression and see if the background displays.
Let me know if this helps.