When I load the file xxx.s3d I get the message "Invalid rail point position
.Interpolation may be wrong. Check the slices."

• It means that the rail point is not at the right place. Go to the
  design view and change the position of the rail point (right click
  on the rail point, choose "Modify point .. " and click on
  the box "rail").

I loaded the V7 and opened a file that I have used in V6 but up on the
nose I am having trouble with the point, it will not work properly
and has altered the file from V6.

• In the version 7 the thickness is computed as the difference the
  deck which was computed as the sum of the bottom and the
  thickness. In other words in the version 7, the deck is now a
  true bezier curve (easier to modify) and the thickness is a
  false one. To translate a V6 model to a V7 model, Shape3d
  search for the bezier curve which fit the deck. The new deck
  is therefore sligthly different from the version 6.

I can not set my concave depth at middle point of slices. It just doesn't
allow me to set depth of concave at the middle.

• With the version 7th the profile view is the stringer and no more
  the side view. It's more consistent to the way the
  measurements are taken.
  So, you can't move the two middle point of the slice. Moreover
  it avoid to change the shape of the slice when you move that
  points up or down as before.

You don't have a red analyser curve any more, this is a major problem.

• To display the curvature (red curve) right click and choose
  Display / Curvature. It shows the curvature when a control point
  is selected.
  

I get weird bumped cutting lines at nose and tail.

• Your nose and tail slices are too different from the previous
  slice and the program don't succeed to compute a smoothed
  meshing. The best way to fix that is to copy the previous slice and
  paste it on the nose or tail slice :
  • Go to the outline view and select the second slice
    (from tail)
  • Go back to the slice view and click on the "Copy"
    button on the tool bar
  • Return to the outline view and select the tail slice
  • Go again the the slice view and click on the "Paste"
    button

I do not want a blank in cnc version how do I delete it ? I always set my
file at a work offset position once blank is clamped.

• If you really don't want a blank you have just to check the box
  "Auto" and specify all the margins at 0. The blan
  k will be the same as the board.
  But I think you should be wrong to do that : the blank is the only
  way to control exactly the position of the board with respect to
  the rotation axis bewteen the clamps (see point ..). With a blank
  you can use the automatic blank and it's margin to specify the
  position of the board related to the clamp.

When I try to compute the cutting path it tell me to go back to slices and
hit apex button.

• You get this message if there is no apex point defined for EACH
  slice (nose and tail included). The new option "Rail"
  enable you to set the separation line on the rail instead of the
  apex. It's usefull for square rails.

The cutter is way above design is that 0x0y0z and what is the distance
to the horizontal rotating point from the bottom of the cutter ?.

• The height of the rotating axis is given by the "Z level of rotation
  axis" in the "Positions and blank" tab of the CNC dialog box.

How do you set your rail heights and in your new files are all the boards
without rail tuck or can you still create a bottom rail.

• I think that your are talking about the square rail option ?
  If yes, you can set the height of the rail with the apex point.
  You can of course still create the bottom rail as previously
  if you don't check the "Square rail".