Not open Front Office in Prestashop 1.4.0.17

[bolzoni]

After installing version 1.4.0.17 of Prestashop, many members say
can not open the Front Office Servers Windows.

I also had the same problem and resolved as follows:

Open / config / config.inc.php;
on line 29

@ init_set ('display_errors', 'off');

to replace

@ init_set ('display_errors', 'on');

close the file.

In php.ini

extension = php_mbstring.dll

close php.ini

Restart the Apache server.

Thanks.