PHP Session is being created for every page - php

Question

So problem is as the title says php session is being created for every page. So when I want to get a variable from session like this
session_start();
echo $_SESSION['error'];
It says "undefined index".
The problem is, in fact 'error' index defined but not in the current session since php creates new session for every page.
How can I solve this?
Note: I put session_start(); to every pages' first line, and before header("location:error.php") I put session_write_close(); and after the header there is die(); method too. I'm working on localhost. Using Latest version of WAMP and JETBRAINS PHPSTORM.
EDIT---------------------
This is where I define my session for error(this is from login.php page)
session_start();
$_SESSION['error'] = "Enter both username and password";
header('Location:error.php');
exit;
When the code above run, a session named "sess_amvrseubtusk0dpuo4fs35r0q1" is created and it has this line in it
error|s:32:"Enter both username and password";
And this is where I want to read session (this is from error.php page)
session_start();
echo 'SESSION: ' . $_SESSION['error'];
When the code above run, a session named "sess_m08lf25stbhg75gj2h0n0vose0" is created and it is empty.
I have all two of the created session files in my Session directory so 1 session file for each page.
EDIT 2----------------------------------
Here my php.ini file
http://pastebin.com/JNsPdzjH
EDIT 3----------------------------------
New php.ini file with changes "c:/wamp/tmp" to "C:/Users/nerzid/PhpstormProjects/Deneme/Session"
http://pastebin.com/Zaz37UPC

Answer 1

This posted as per your originally posted question should people wonder.
You may not have defined anything to $_SESSION['error'], least not with what you posted for code:
session_start();
echo $_SESSION['error'];
You would first need to assign something to it.
For example:
session_start();
$_SESSION['error'] = "Error.";
echo $_SESSION['error'];
Then on subsequent pages, you check if the session is set => isset() and/or empty => empty() or not.
I.e.:
if(isset($_SESSION['error']) && !empty($_SESSION['error'])){
echo $_SESSION['error'];
}
else{
echo "Session is not set";
// set a new one
}
If session is set from a variable example:
session_start();
$_SESSION['error'] = "Error.";
$error_x = $_SESSION['error'];
echo $error_x;
Also, when using header, add exit;
header("location:error.php")
exit;
always.
Sidenote:
Since you're working off of localhost, make sure the folder is writeable.