500 error after update

In phpmyadmin search :

SELECT *
FROM wp_options
WHERE option_name="template"
OR option_name="stylesheet"
OR option_name="current_theme";

then :

UPDATE wp_options SET option_value="yourthemename" WHERE option_name="template";
UPDATE wp_options SET option_value="yourthemename" WHERE option_name="stylesheet";
UPDATE wp_options SET option_value="yourthemename" WHERE option_name="current_theme";

or if you want to go back to default (presuming some default exists)

SET option_value="default" WHERE option_name="template";

UPDATE wp_options SET option_value="default" WHERE option_name="stylesheet";

UPDATE wp_options SET option_value="default" WHERE option_name="current_theme";

note :

• template – the “Theme Name” as defined in style.css
• stylesheet – the actual name of your theme folder
• current_theme -the actual name of your theme folder