Upgrade 7.8646 Failed - DB Error

JInstaller: :Install: Error SQL DB function failed with error number 1091

    Can't DROP 'callback_method'; check that column/key exists SQL=ALTER TABLE `zegrk_js_res_notifications` DROP COLUMN `callback_method` , DROP COLUMN `callback_class` , DROP COLUMN `callback_file` ;

    SQL =

    ALTER TABLE `#__js_res_notifications` 

        DROP COLUMN `callback_method` , 

        DROP COLUMN `callback_class` , 

        DROP COLUMN `callback_file` ;

    Component Update: SQL error file DB function failed with error number 1091

    Can't DROP 'callback_method'; check that column/key exists SQL=ALTER TABLE `zegrk_js_res_notifications` DROP COLUMN `callback_method` , DROP COLUMN `callback_class` , DROP COLUMN `callback_file` ;

    SQL =

    ALTER TABLE `#__js_res_notifications` 

        DROP COLUMN `callback_method` , 

        DROP COLUMN `callback_class` , 

        DROP COLUMN `callback_file` ;

    Package Install: There was an error installing an extension: com_cobalt.v.7.8646.zip

After verify table I discovered that callback_method, callback_class and callback_file DO NOT exists!

Please advise. Cobalt reports as 7.8615 (upgrade fails).