Hallo, Piotr.
When I try to activate plugin "GK Tabs" I see this mistake:
Fatal error: Cannot redeclare class Gk_Tabs_Widget in /home/r/russiatree/public_html/wp-content/plugins/gk-tabs/gk-tabs.php on line 751.
And one's more whan I activate plugin "GK News Show Pro" after that I cannot to use customize.php (Appearantce->Theme options->), I get this mistake:502 Bad Gateway.
Help me please.
Thanks in advance.