I have not touched this project for eternity and this thing worked in 2.3.0 but not in 2.3.3

<?php
class SeminarAll  extends Page {
   static $db = array(
   );
}

class SeminarAll_Controller extends Page_Controller {

function SeminarSearchFormAll(){
return new Form(
$this,
"SeminarSearchFormAll",
new FieldSet( new FormAction('doSeminarSearchAll','Display All Seminars'))
);
}

function doSeminarSearchAll($data,$form){
$results = new DataObjectSet();
$resultss = DataObject::get("Seminar", "", "`seminardate`,`seminartimestart`");
$results->merge($resultss);
$results->sort('seminartimestart');
$results->sort('seminardate');
return $this->customise(array('SeminarSearchResults' => $results))->renderWith(array('SeminarSearch_results'));
}
}
?>

It complains (in DevMode) about

function doSeminarSearchAll($data,$form){

but would not complain about
function doSeminarSearchAll(){

(albeit the latter does not work)

Anything I am missing? Thank you in advance

Victor

The form actions should be the fourth parameter of the Form constructor (not the third as in your example).
http://doc.silverstripe.org/doku.php?id=form

function SeminarSearchFormAll(){
	return new Form(
		$this,
		"SeminarSearchFormAll",
		... your form fields? ...,
		new FieldSet( new FormAction('doSeminarSearchAll','Display All Seminars'))
	);
}