Duplicates True/False with errors

[pto160]

I have a formula that identifies if there is duplicates in a column.

=MAX(COUNTIF(B1:B30,B1:B30)*(B1:B30<>""))>1

How would I add a condition to exclude errors like #N/A in a column?

 

[steve the fish]

Same formula with an IFERROR should sort it out.

=MAX(COUNTIF(B1:B30,B1:B30)*(IFERROR(B1:B30<>"",0)))>1

Enter CNTL-SHIFT-ENTER.

 

[pto160]

Thank you so much. It works great.