Can't execute query

select cm.*,rs.name as revenue,es.name as employee,s.short_name,ind.title,s.state_name,c.countries_name,c.countries_iso_code_3 from cto_company_master as cm, cto_revenue_size as rs, cto_employee_size as es, cto_industry as ind, cto_state as s, cto_countries as c where cm.company_revenue=rs.id and cm.company_employee=es.id and cm.state = s.state_id and cm.country=c.countries_id and cm.industry_id=ind.industry_id and cm.company_id = "502511"

MySQL Error: MySQL server has gone away

This script cannot continue, terminating.