Printer had been turned Off overnight with no paper in paper tray. When turned On this AM error notice reappeared, as had done several times when instructions followed with printer also being turned On And Off.
Have opened that part of printer giving access to ink cartridges, the only "opening part" on the printer, I can see no visible pieces of paper, have checked "exit slot" with torch, no paper seen. Do not recall any "torn" printed sheets of paper recently nor having to "pull" any "part loaded" unprinted sheets from the paper tray which may have got torn in the process.
Many thanks for your assistance, warranty out of date so tis a "worst case scenario" to which one can only say "rollocks".