Can not delete the copied value

[Legandary23]

This is the error message:
  [Ljava.lang.Object; cannot be cast to [Lorg.zkoss.zss.model.CellRegion;

I was copying the data from the old DataSpreadFall2017 Sheet to the new server. When I try to delete a single cell or clear the content of the copied region, the error pops out.