I have a complicated indirect function reference. After about 24 sheets it
is not bringing back the correct cell value (through a vlookup). Is there
some limit to the amount of memory required for the use of Indirects?

FYI, I have a large workbook with 60+ worksheets, and an indirect function
which references (1) the cell in the workbook which contains the name of
another workbook, (2) the tab in this other workbook, and (3) the vlookup
range on that particular sheet.

My formula looks like this:
=VLOOKUP(F6,INDIRECT("'["&Index!P8&"]"&J5&"'!$b$152:$h$174"),3). This
formula works fine for the first 24 tabs, but then subsequent tabs bring back
identical values. - - I've checked the vlookup portion of the formula and
that works fine.

Any advice? I am considering not leveraging the Indirect function so much
in my spreadsheets. Thanks!