Reason 1: It’s possible that some files on your server have permissions settings that doesn’t allow PHP to edit/access them. The following files/directories should be both readable and writable by PHP:

• whole /data folder,
• whole /upload folder + its subfolders,
• /php/config/app.settings.php file,
• /php/config/parameters.php file.

Reason 2: It’s possible that your web server is missing some required PHP extension. Please make sure that both of the following PHP extensions are installed and enabled on your web server:

• PDO,
• pdo_mysql.

If you don’t know how to do this, please contact your web hosting company. They should be able to do it for you.

Reason 3 (less likely): It’s also possible that you have “magic quotes” installed on your web server. Try disabling this feature and running the application again.

More info on “magic quotes”: http://www.php.net/manual/en/security.magicquotes.php

After making any of those changes, go to admin panel’s Settings tab and click Reset to defaults button. If errors are still in place, you should additionally reinstall the application.

To install the updated version, you need to first re-download the item from codecanyon and copy the new files on your web server. After that, run the same installation process as originally done. Note that you can keep your database intact with all of the data (you don’t have to delete and re-create it again). If you want the database to stay as it is, just don’t run uninstallation of the previous version.

If you want to feel more safe, you can always install the new version under a different directory (with the old one still working) and test it before finally switching.

Keeping current configuration and settings after update
There are some files and directories you can keep on your server when updating, so that your configuration, application settings and uploaded avatars stay intact in the new version. For that, upload everything, but those items:

• /php/config/parameters.php
  (stores main configuration and database settings),
• /php/config/app.settings.php
  (stores settings from the Settings tab of the administration panel),
• /upload/avatars
  (stores your custom avatars).

Open the php/app.php file and there change the following line:

error_reporting(0);

to this one:

error_reporting(E_ALL | E_STRICT);

After that errors should be displayed in the browser.