502 Bad Gateway when try to open themes/plugins/update after updating to 3.7.1

Got the weird issue

After the autoupdate option appeared an error 502 Bad Gateway ngnix

Site still works but all plugins turned off and when i try top open plugins/themes/update links 502 Bad Gateway error appears again.

I have reinstalled WP to another folder, and copied wp_config.php to include old database but shere’s still 502 error when i try to change theme or press the button to update the core.

Also, there’s no ability to install new plugin anymore – i have a clean area right to admin menu

Any ideas what’s wrong with it?