What causes Google Sheets FILTER() range mismatch? [closed]

This formula

=FILTER(dJournal!$A$5:I,dJournal!$B$5:B>"1")

gives me this error:

FILTER has mismatched range sizes.Expected row count: 998. column count: 1.Actual row count: 1, column count: 1.

I get the same error for

=FILTER(dJournal!$A$5:I,ARRAYFORMULA(ISDATE(dJournal!$A5:A)))

despite the explanation

•condition1 - A column or row containing true or false values corresponding to the first column or row of range, or an array formula evaluating to true or false.

at Google Docs Support

(Their examples do not match that description)

I guess I'm missing some simple rule about how to use this function, but I'm baffled.