Eliminating that dreaded "#num!" from a variable list

I have a list in Col B which is a constant 66 numbers.

I needed to sort out duplicates so in Col C I placed
=IF(B1="","",IF(COUNTIF($B$1:B1,B1)=1,ROW(),"")) to eliminate any repeat numbers.

In Col D I placed =IF(ROW(B1)>COUNT($C$1:$C$66),"",INDEX($B$1:$B$66,MATCH(SMALL($C$1:$C$66,ROW(A1)),$C$1:$C$66,0))) to list only the non-repeating numbers.

In Col E I placed
=SMALL($D$1:$D$66,ROW(A1)) to sort in descending order the numbers, because its a variable list depending on the "repeat" numbers would vary in length.

I'm looking for a way to eliminate "#NUM!" and leave those cells blank...

See attached sample.Attachment 182276

=iferror(small($d$1:$d$66,row(a1)),"")