vmagal1 wrote...
Well I figured out the problem. I was using the mode function on
cells that
were calculated using a formula. I guess it didn't like that.
....

Not the problem. If I enter the formula

=INT(1+5*RAND())

in A1:A20, MODE(A1:A20) works just fine, returning the mode of the
formula-generated values in A1:A20.

Far more likely your problem is due to number formatting that makes
many of your formulas appear to produce the same value when there are
actually differences. If I enter the formula

=5*RAND()+0.5

in B1:B20 and replace the formulas in A1:A20 with

A1:
=ROUND(B1,0)

and format A1:B20 as numbers with zero decimal places, A1:A20 and
B1:B20 appear identical, but MODE(A1:A20) returns a number while
MODE(B1:B20) returns #N/A.