Show cell as empty if referenced one is empty

Hi,

Re the worksheet (in the image), I have the following formula in B4, which works perfectly - when there's data.

=LET(u,IFERROR(UNIQUE(FILTER('All Completed Runs'!D4:D357,('All Completed Runs'!E4:E357<>"")*('All Completed Runs'!D4:D357<>"UK Crown Dependencies & UK Overseas Territories"))),""),c,COUNTIF('All Completed Runs'!D:D,u),SORTBY(HSTACK(u,c),c,-1))

However, when there isn't data in A4 and/or B4 I would like the count column (C) to also appear empty. I have tried adding various if(A4="","", type things into it, in various places, but nothing seems to work - they all mess up the LET formula. Is there something I can do to achieve this?

Thanks in advance!

Olly.

Also posted on MREXCEL.COM: https://www.mrexcel.com/board/thread...empty.1254622/IMG_7258.jpeg