Error with upload some photos

Hi Everyone,

First let congrats this amazing script, its making work a lot quicker and easier for many tasks.

So, the problem is I am trying to upload an image using the grocery crud using of course the

$crud->set_field_upload();

everything is going well for some file uploads but some of it is returning an error "An error has occurred on uploading.", here the console response :

<html>
<head><title>413 Request Entity Too Large</title></head>
<body bgcolor="white">
<center><h1>413 Request Entity Too Large</h1></center>
<hr><center>nginx</center>
</body>
</html>
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Thank you

Amine Kacem