While the Interval Table Format, Interval Table, and Point Count registers from the Spline Download Area can be downloaded in any order, the Spline Point table must be downloaded in order, from the first point to the last.
If you feel that you did do this then you may have received this error because one of your previous downloads was in error. For example, if you downloaded the first 20 points of a 40-point spline and it had a parameter error then the RMC will expect you to start over your download. If you continue the download instead, perhaps not checking for the parameter error after the first download, then you will get this parameter error.
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