Possible solutions of your questions

Hello. what changes did you do on the website?

we see that you re-uploaded the files, why?

for what? we`re you yesterday everything moved and configured and you have taken all  messed up That he has changed?  what did you change in the settings?

here are the errors which now produces the website

[23-Jun-2015 08:15:44 UTC] PHP Warning: mysqli::query() [<a href=`mysqli.query`>mysqli.query</a>]: couldn`t fetch mysqli in /home/fatfamil/public_html/happy-burger.ru/api/Database.php on line 81
[23-Jun-2015 08:15:44 UTC] PHP Warning: Database::results() [<a href=`database.results`>database.results</a>]: couldn`t fetch mysqli in /home/fatfamil/public_html/happy-burger.ru/api/Database.php on line 127
[23-Jun-2015 08:15:44 UTC] PHP Warning: in /home/fatfamil/public_html/happy-burger.ru/api/Database.php on line 127
[23-Jun-2015 08:15:44 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/fatfamil/public_html/happy-burger.ru/api/Pages.php on line 51
[23-Jun-2015 08:15:44 UTC] PHP Warning: mysqli::query() [<a href=`mysqli.query`>mysqli.query</a>]: couldn`t fetch mysqli in /home/fatfamil/public_html/happy-burger.ru/api/Database.php on line 81
[23-Jun-2015 08:15:44 UTC] PHP Warning: mysqli::query() [<a href=`mysqli.query`>mysqli.query</a>]: couldn`t fetch mysqli in /home/fatfamil/public_html/happy-burger.ru/api/Database.php on line 81
[23-Jun-2015 08:15:44 UTC] PHP Warning: Database::results() [<a href=`database.results`>database.results</a>]: couldn`t fetch mysqli in /home/fatfamil/public_html/happy-burger.ru/api/Database.php on line 127
[23-Jun-2015 08:15:44 UTC] PHP Warning: in /home/fatfamil/public_html/happy-burger.ru/api/Database.php on line 127
[23-Jun-2015 08:15:44 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/fatfamil/public_html/happy-burger.ru/api/Pages.php on line 51
[23-Jun-2015 08:15:44 UTC] PHP Warning: mysqli::query() [<a href=`mysqli.query`>mysqli.query</a>]: couldn`t fetch mysqli in /home/fatfamil/public_html/happy-burger.ru/api/Database.php on line 81

in what sense unnecessary? we see the problem when working with the database. yesterday, after the migration everything worked. what has changed today?