HMRC online submission Error 6791

While submitting your SA100 returns, the HMRC (Government Gateway) is returning the following validation message:

Error Number: 6791

Error Location: /hd:GovTalkMessage[1] /hd:Body[1] /MTR:IRenvelope[1]/ MTR:MTR[1]

Error Type: business

Error Text: There must be an entry in one of [FSE99], [LUN63], [SPS23], [FPS23] or [SSE35] as there is an entry in one of the boxes [FSE75], [LUN52], [SPS18], [FPS18] or [SSE30] and there is an entry in [YPD1], and box [YPD1] date + [65 years] is prior to the beginning of the return year or on 6 April of the return year.

This message suggest that you are attempting to submit a return for a Tax payer who is 65 years or older. You may have an Income entry that results to Class 4 NIC calculation but have not ticked other relevant boxes.

HMRC server suggests there must be an entry in one of the following field (only in the form you have selected):

Self Employment Full Box 99, or
Lloyds Underwriters Box 63, or
Partnership short Box 23, or
Self Employment short Box 35