The file containing contour value specifications can include the following:
- Any line that starts with a nonnumeric value will be ignored and treated as a comment line.
- A line with three values will be treated as base, contour interval, and indexed contour.
- A line with four values will be from, to, by, and indexed contours.
- A line with a single value will be an explicit contour value.
Correct the line and try again.