Hi Daniel,
you have some typos in your code.Please try this one:
$existFeedback = false;
$feedbackName = 'feedback1'; //"feedback1" is the name of one feedback in my course that exist
$feedbacks = get_all_instances_in_course("feedback",$course);
foreach ($feedbacks as $feedback) {
if($feedbackName == $feedback->name){
$existFeedback = true;
}
}
echo $existFeedback;
To find such typos you should switch on the debugging all the time you try some new code.
Best regards
Andreas