Fresh Install – Cannot modify header information, wp-config.php:1

It’s unlikely to relate to anything other than blank space or a newline at the start of the wp-config file.

Are you 100% sure?
I ask this simply because it’s just the code in the wp-config-sample.php

<?php
/**
 * The base configurations of the WordPress.
 *
 * This file has the following configurations: MySQL settings, Table Prefix,
 * Secret Keys, WordPress Language, and ABSPATH. You can find more information by
 * visiting {@link https://codex.www.ads-software.com/Editing_wp-config.php Editing
 * wp-config.php} Codex page. You can get the MySQL settings from your web host.
 *
 * This file is used by the wp-config.php creation script during the
 * installation. You don't have to use the web site, you can just copy this file
 * to "wp-config.php" and fill in the values.
 *
 * @package WordPress
 */

// ** MySQL settings - You can get this info from your web host ** //
/** The name of the database for WordPress */
define('DB_NAME', 'putyourdbnamehere');

/** MySQL database username */
define('DB_USER', 'usernamehere');

/** MySQL database password */
define('DB_PASSWORD', 'yourpasswordhere');

/** MySQL hostname */
define('DB_HOST', 'localhost');

/** Database Charset to use in creating database tables. */
define('DB_CHARSET', 'utf8');

/** The Database Collate type. Don't change this if in doubt. */
define('DB_COLLATE', '');

/**#@+
 * Authentication Unique Keys.
 *
 * Change these to different unique phrases!
 * You can generate these using the {@link https://api.www.ads-software.com/secret-key/1.1/ www.ads-software.com secret-key service}
 * You can change these at any point in time to invalidate all existing cookies. This will force all users to have to log in again.
 *
 * @since 2.6.0
 */
define('AUTH_KEY', 'put your unique phrase here');
define('SECURE_AUTH_KEY', 'put your unique phrase here');
define('LOGGED_IN_KEY', 'put your unique phrase here');
define('NONCE_KEY', 'put your unique phrase here');
/**#@-*/

/**
 * WordPress Database Table prefix.
 *
 * You can have multiple installations in one database if you give each a unique
 * prefix. Only numbers, letters, and underscores please!
 */
$table_prefix  = 'wp_';

/**
 * WordPress Localized Language, defaults to English.
 *
 * Change this to localize WordPress.  A corresponding MO file for the chosen
 * language must be installed to wp-content/languages. For example, install
 * de.mo to wp-content/languages and set WPLANG to 'de' to enable German
 * language support.
 */
define ('WPLANG', '');

/* That's all, stop editing! Happy blogging. */

/** Absolute path to the WordPress directory. */
if ( !defined('ABSPATH') )
	define('ABSPATH', dirname(__FILE__) . '/');

/** Sets up WordPress vars and included files. */
require_once(ABSPATH . 'wp-settings.php');

That’s it! I don’t see spaces anywhere (same thing after I’ve defined database name, username and pwd).

So, there’s absolutely anything else I should look at whenever I have the error for wich I started this thread?

Yep the error is fairly specific. How are you editing / transfering the file?

Take the file from the folder and I put in Filezilla remote server.

It could be your editor at fault, try using notepad+ or vim.

Hi! I was having exactly the same problem! There was this error and there was no blank space before <?php… How did i solve it?

GET PREPARED!

Simple! Just download a fresh wordpress zip and extract it. Don’t create any wp-config.php file. Just leave the files as they come when they are extracted. Then upload the folder (or just it’s content) to your server and try to access wp-admin/install.php by your browser. WordPress will say that the “wp-config.php” file was not created and will ask you if you want to make it using your browser. Say yes, type the settings and be very happy :D!!!!!!!