I made a questionnaire in PHP. When I try to submit after grading, I get the following message:
The error that I get
I have 3 php pages. 1 for the questionnaire, 1 for the main and 1 for the post method.
Here are the 2 .php files that I need to adjust more. After submitting it goes back in mainpage

<h3>ΓΕΝΙΚΕΣ ΠΛΗΡΟΦΟΡΙΕΣ</h3>
<form method="POST" action="qaquploadmarks.php">

how the questions look

<input type="submit" style ="background-color:#162068" class="btn btn-primary" onclick=" return confirm('Η υποβολή είναι οριστική, πατήστε OK για επιβεβαίωση.')" name="qaquploadmarks" value="Αποθήκευση και Υποβολή" />
</form>

Here I receive the data from the tables, The only problem is when I go to the form with the questions. (They are 55, I have the 1 just for presentation)
And here is the post method via picture cause I couldnt post:
Post method

Lastly I have the Stored procedure which has 55 parameters a and n:
The stored procedure

The questionnaire looks like this: how the page looks
All the other functions work.