Excel Filter results in #value

Question

I'm trying to filter a list. If I use the formula...

=FILTER('Task List'!G:G,'Task List'!$Z:$Z=$L$1,"")

... it works and I get results.

The problem is, the data I want returned could be in any of the columns from G through O.

But as soon as I put...

=FILTER('Task List'!G:O,'Task List'!$Z:$Z=$L$1,"")

... I get a spill error.

Now, if I try to limit it to get rid of the spill error and put...

=FILTER('Task List'!G4:O10000,'Task List'!$Z:$Z=$L$1,"")

I get a #Value error.

I want to return all results from G4 through O10000, if the results in column Z match the word in L1... I'm sure I'm missing something simple here, but not sure what it is.

Thanks in advance!