Moving CI website to another server - only blank page showing

Tha domain has changed.
The /application/logs/ folder is empty, only an index.html is there... I don't know, why?

Have you checked $config['log_threshold'] in your config.php?
or the log_path and is the log_folder able to be written to?
is environment set to development?

Thanks! The log_threshold was set to 0, I set it to 4. And I gave write permission to the log folder.
I got this log, when I try to load the page:

ERROR - 2018-07-02 12:21:10 --> Severity: Notice  --> Only variable references should be returned by reference /var/www/html/szig/ci/core/Common.php 257
DEBUG - 2018-07-02 12:21:10 --> Config Class Initialized
DEBUG - 2018-07-02 12:21:10 --> Hooks Class Initialized
DEBUG - 2018-07-02 12:21:10 --> Utf8 Class Initialized
DEBUG - 2018-07-02 12:21:10 --> UTF-8 Support Enabled
DEBUG - 2018-07-02 12:21:10 --> URI Class Initialized
DEBUG - 2018-07-02 12:21:10 --> Router Class Initialized
DEBUG - 2018-07-02 12:21:10 --> No URI present. Default controller set.
DEBUG - 2018-07-02 12:21:10 --> Output Class Initialized
DEBUG - 2018-07-02 12:21:10 --> Security Class Initialized
DEBUG - 2018-07-02 12:21:10 --> Input Class Initialized
DEBUG - 2018-07-02 12:21:10 --> Global POST and COOKIE data sanitized
DEBUG - 2018-07-02 12:21:10 --> Language Class Initialized
DEBUG - 2018-07-02 12:21:10 --> Loader Class Initialized
DEBUG - 2018-07-02 12:21:10 --> Config file loaded: /var/www/html/szig/application/config/SZIG_ver.php
DEBUG - 2018-07-02 12:21:10 --> Helper loaded: url_helper
DEBUG - 2018-07-02 12:21:10 --> Helper loaded: szig_helper
DEBUG - 2018-07-02 12:21:10 --> Database Driver Class Initialized

In the 257. line of the Common.php:
return $_config[0] =& $config;

I found a possible solution for this error:
https://stackoverflow.com/questions/2834...odeigniter
So I modified the Common.php to this:

Code:

$_config[0] =& $config;
return $_config[0];

But... nothing happened. :/ In Firefox, only a blank page showing, and in Chromium, I got a HTTP error 500.

Do NOT edit common.php! Put it back the way it was.

How did you place the files and folders of CodeIgniter relative to the website root (public) folder?

The website root folder is the /var/www/html/, and I put the webpage to the /var/www/html/szig/ folder.

Please describe the contents (files and folders) in /var/www/html/szig/

Is index.php in /var/www/html/szig/?

Have you set up a virtual host that sets the DocumentRoot to /var/www/html/szig/?

If you have set up a virtual host what is the ServerName you gave it?

Do NOT edit common.php! Put it back the way it was.

Ok, I put it back.

How did you place the files and folders of CodeIgniter relative to the website root (public) folder?

The website root folder is the /var/www/html/, and I put the webpage to the /var/www/html/szig/ folder.

Please describe the contents (files and folders) in /var/www/html/szig/

Is index.php in /var/www/html/szig/?

Have you set up a virtual host that sets the DocumentRoot to /var/www/html/szig/?

If you have set up a virtual host what is the ServerName you gave it?

The directory structure:
https://pastebin.com/hJeA8yk5

The directory structure with files:
(this is a big file...) http://tbc_z87.fw.hu/temp/ktfa2.txt


The index.php is in the /var/www/html/szig/public_html folder.
I don't  set virtual host in the apache config.

New information: I put the error_reporting(E_ALL), and ini_set('display_errors', 1) lines to the index.php. I got some errors:

A PHP Error was encountered
Severity: Notice
Message: Only variable references should be returned by reference
Filename: core/Common.php
Line Number: 257

Fatal error: Uncaught Error: Call to undefined function mysql_connect() in /var/www/html/szig/ci/database/drivers/mysql/mysql_driver.php:73 Stack trace: #0 /var/www/html/szig/ci/database/DB_driver.php(115): CI_DB_mysql_driver->db_connect() #1 /var/www/html/szig/ci/database/DB.php(148): CI_DB_driver->initialize() #2 /var/www/html/szig/ci/core/Loader.php(346): DB(Array, NULL) #3 /var/www/html/szig/ci/core/Loader.php(1171): CI_Loader->database() #4 /var/www/html/szig/ci/core/Loader.php(152): CI_Loader->_ci_autoloader() #5 /var/www/html/szig/ci/core/Controller.php(51): CI_Loader->initialize() #6 /var/www/html/szig/application/core/SZIG_Controller.php(12): CI_Controller->__construct() #7 /var/www/html/szig/application/controllers/main.php(7): SZIG_Controller->__construct() #8 /var/www/html/szig/ci/core/CodeIgniter.php(308): Main->__construct() #9 /var/www/html/szig/public_html/index.php(251): require_once('/var/www/html/s...') #10 {main} thrown in /var/www/html/szig/ci/database/drivers/mysql/mysql_driver.php on line 73

So... this is a database error, because the programmer used obsolote function?

(Anyway sorry for the stupid questions, I am newbie in CodeIgniter...)

Do you use the mysql driver in your database.php? see 'dbdriver' => 'mysql',
If yes, don't use that driver use the mysqli driver.
That should be ' dbdriver' => ' mysqli',

André

I suspect the fatal error is due to your file structure. It's going to be awhile before I can parse it all.