Remove the comma before "et al."

Warning²Federal courts, Illinois courts21st and 22nd editions

Where a work has more authors than the form names individually, the first author's name is followed directly by “et al.”, with no comma between them.¹

1. 1R. 15.1(b) More than three authors; R. 15.1 Author; B15.1 Full Citation.
2. 2A warning: the form is usually wrong under the rule in note 1, and context can justify it.