Error 'Cannot redeclare ctools_menu_add_tab()' after migrating website
You have ctools installed twice, in:


sites/all/modules/ctools
sites/all/modules/ckeditor/ctools


Obviously the second path must have been mistake. If you can acces your page, disable ctools and then remove second instance. If you can't, try to do it using drush. If that fails, too, consider re-migration, this time properly. If all else fails, you may try to simply remove second instance and call update.php to perform some cleanup.