Fatal error after disabling ctools
Its really hard to figure out a solution for your issue without trying different options; but I hope the following instructions will help you.


Backup your current database
Open phpMyAdmin or any desirable MySQL administration tool.
Delete all ctools modules from system table or run this query 

DELETE FROM system WHERE name LIKE '%ctool%'
Drop ctools tables ctools_css_cache, ctools_custom_content, ctools_object_cache or run these queries 

DROP TABLE ctools_css_cache

DROP TABLE ctools_custom_content

DROP TABLE ctools_object_cache
truncate all cache tables (cache table and all tables with prefix cache_), example of truncate query 

TRUNCATE TABLE cache