I am writing a conditional format formula and am getting the error: "You may
not use references to other worksheets or workbooks for conditional
formatting" But, I'm not referring to another worksheet in my formula.

Here's the Conditional Format formula in G19:

=AND(G19="",(NETWORKDAYS(TODAY(),F19,holidays))1)

What it does is make sure cell G19 isn't blank and then checks the number of
days between today and cell F19, minus my named range of 'holidays.' If
that's greater than 1, then turn it red.

What am I missing?