I have a formula that was working last week and today I get the ominous #REF!
error.

The value in cell K44 equals 11

Here's the formula:
=SUMPRODUCT(--(WEEKDAY(ROW(INDIRECT(TODAY()&":"&TODAY()+(K44/2))))/7))

Last week the value in cell K44 equaled 36; don't know if this helps.

Thanks for looking.

El Bee