Quality assurance testing and CUTTING EDGE

[Oleg06]

After installing my theme, I was unable to login to admin panel.

Code:

Notice: Trying to get property of non-object in /home/u925819/quicklysite.ru/html/plugins/p01-contact_gs.php on line 69

Notice: A session had already been started - ignoring session_start() in /home/u925819/quicklysite.ru/html/plugins/feedback.php on line 36

Warning: Cannot modify header information - headers already sent by (output started at /home/u925819/quicklysite.ru/html/plugins/p01-contact_gs.php:69) in /home/u925819/quicklysite.ru/html/admin/inc/cookie_functions.php on line 25

Warning: Cannot modify header information - headers already sent by (output started at /home/u925819/quicklysite.ru/html/plugins/p01-contact_gs.php:69) in /home/u925819/quicklysite.ru/html/plugins/i18n_base/backend.class.php on line 7

I removed plugins causing errors, entered the admin panel.

Code:

Notice: Trying to get property of non-object in /home/u925819/quicklysite.ru/html/plugins/p01-contact_gs.php on line 69

Notice: A session had already been started - ignoring session_start() in /home/u925819/quicklysite.ru/html/plugins/feedback.php on line 36

Warning: Cannot modify header information - headers already sent by (output started at /home/u925819/quicklysite.ru/html/plugins/p01-contact_gs.php:69) in /home/u925819/quicklysite.ru/html/admin/inc/cookie_functions.php on line 25

I saw the error, and for some reason the buttons were above.
http://prntscr.com/j8ke1r

The site looks like this.
http://quicklysite.ru/
And should look like this.
http://demo.getsimplethemes.ru/shop-en/

Not able to disable plugins in the admin panel.

The server's all right.
http://prntscr.com/j8khnv

It's a little scary for me