White Page PHP data insert : Good day comrades.
I am looking for answers about 10 hours on stackoverflow and google, have read about 50 same questions, every time its different, my head is allready has been boiling. I have a simple PHP CRUD application with OOP.
It has a connection to BD(it works, my data gets from bd and i could see it at my index.php in opera/safari), has 'add' action(it doesn't work - white page), 'edit' action (it doesn't work - white page), 'delete' action (it works). 

I am using in my project:

-PHPSTORM

-PHP CLI interpreter 7.2

-PHP language level 5.6

add.php code:

    <html>
    <head>
	<title>Add Data</title>
    </head>
    <body>
    <?php
    include_once("classes/Crud.php");
    include_once("classes/Validation.php");
    $crud = new Crud();
    $validation = new Validation();
    if(isset($_POST['Submit'])) {	
	$name = $crud->escape_string($_POST['name']);
	$age = $crud->escape_string($_POST['age']);
	$email = $crud->escape_string($_POST['email']);	
	$msg = $validation->check_empty($_POST, array('name', 'age', 'email'));
	$check_age = $validation->is_age_valid($_POST['age']);
	$check_email = $validation->is_email_valid($_POST['email']);
	if($msg != null) {
		echo $msg;		
		echo "<br/><a href='javascript:self.history.back();'>Go Back</a>";
	} elseif (!$check_age) {
		echo 'Please provide proper age.';
	} elseif (!$check_email) {
		echo 'Please provide proper email.';
	}	
	else { 
		$result = $crud->execute("INSERT INTO users(name,age,email) VALUES('$name','$age','$email')");
		echo "<p style='color=green'>Data added successfully.";
		echo "<br/><a href='index.php'>View Result</a>";
	}
    }?>
    </body>
    </html>

edit.php

    <?php
    include_once("classes/Crud.php");
    $crud = new Crud();
    $id = $crud->escape_string($_GET['id']);
    $result = $crud->getData("SELECT * FROM users WHERE id=$id");
    foreach ($result as $res) {
	$name = $res['name'];
	$age = $res['age'];
	$email = $res['email'];
    }
    ?>
    <html>
    <head>	
	<title>Edit Data</title>
    </head>
    <body>
	<a href="index.php">Home</a>
	<br/><br/>	
	<form name="form1" method="post" action="editaction.php">
		<table border="0">
			<tr> 
				<td>Name</td>
				<td><input type="text" name="name" value="<?php echo 
    $name;?>"></td>
			</tr>
			<tr> 
				<td>Age</td>
				<td><input type="text" name="age" value="<?php echo 
    $age;?>"></td>
			</tr>
			<tr> 
				<td>Email</td>
				<td><input type="text" name="email" value="<?php echo 
    $email;?>"></td>
			</tr>
			<tr>
				<td><input type="hidden" name="id" value=<?php echo 
    $_GET['id'];?>></td>
				<td><input type="submit" name="update" value="Update">
    </td>
			</tr>
		</table>
	</form>
    </body>
    </html>

editaction.php

    <?php
    include_once("classes/Crud.php");
    include_once("classes/Validation.php");
    $crud = new Crud();
    $validation = new Validation();
    if(isset($_POST['update']))
    {	
	$id = $crud->escape_string($_POST['id']);	
	$name = $crud->escape_string($_POST['name']);
	$age = $crud->escape_string($_POST['age']);
	$email = $crud->escape_string($_POST['email']);	
	$msg = $validation->check_empty($_POST, array('name', 'age', 'email'));
	$check_age = $validation->is_age_valid($_POST['age']);
	$check_email = $validation->is_email_valid($_POST['email']);
	if($msg) {
		echo $msg;		
		echo "<br/><a href='javascript:self.history.back();'>Go 
    Back</a>";
	} elseif (!$check_age) {
		echo 'Please provide proper age.';
	} elseif (!$check_email) {
		echo 'Please provide proper email.';	
	} else {	
		$result = $crud->execute("UPDATE users SET 
    name='$name',age='$age',email='$email' WHERE id=$id");
		header("Location: index.php");
	}
    }
    ?>

If local experts need more information or files from my project i will provide it. Help me, plz.