The signature of eZContentClass::instantiate() is as follows (4.4 until 4.2011 ):

    function instantiate( $userID = false, $sectionID = 0, $versionNumber = false, $languageCode = false, $versionStatus = eZContentObjectVersion::STATUS_INTERNAL_DRAFT )

The default value for $sectionID is 0. $sectionID is solely used when calling eZContentObject::create, passed/forced as 4th argument. 0 is not a valid section number (the "Standard" section is 1), while the default value for the $sectionID parameter in eZContentObject::create is 1, the default section.

The default value for $sectionID in eZContentClass::instantiate() should be 1, the Standard section.

In the current state, some custom code using eZContentClass::instantiate() with no parameter causes Fatal error upon further object edition (in attribute_edit.php, line 472 when setting the 'section' override key).

Steps to reproduce

From a custom module, the following code would lead to a crash :

$replyClass = eZContentClass::fetchByIdentifier( 'forum_reply' );
$reply = $replyClass->instantiate();
$replyObjectID = $reply->attribute( 'id' );

$nodeAssignment = eZNodeAssignment::create( array( 'contentobject_id' => $replyObjectID,
                                                   'contentobject_version' => 1,
                                                   'parent_node' => $parentNodeID,
                                                   'is_main' => 1 ) );
$nodeAssignment->store();

return $module->redirectTo( "content/edit/$replyObjectID/1" );