Unserialize() Error after moving the installation directory
After making a back-up of current db,

Try this in phpMyAdmin or mysql console.

TRUNCATE `cache`;
TRUNCATE `cache_block`;
TRUNCATE `cache_bootstrap`;
TRUNCATE `cache_field`;
TRUNCATE `cache_filter`;
TRUNCATE `cache_form`;
TRUNCATE `cache_image`;
TRUNCATE `cache_libraries`;
TRUNCATE `cache_menu`;
TRUNCATE `cache_page`;
TRUNCATE `cache_path`;
TRUNCATE `cache_rules`;
TRUNCATE `cache_token`;
TRUNCATE `cache_views`;
TRUNCATE `cache_views_data`;